TY  - JOUR
AU  - Elezović, Nevenka
AU  - Babić, Biljana M.
AU  - Gajić Krstajić, Ljiljana
AU  - Ercius, Peter
AU  - Radmilović, Velimir R.
AU  - Krstajić, Nedeljko
AU  - Vračar, Ljiljana
PY  - 2012
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/5733
AB  - Platinum nanocatalyst at nano-tungsten carbide was synthesized, characterized and tested for oxygen reduction reaction (ORR) in 0.1 mol dm−3 NaOH, at 25 °C. Tungsten-carbide islands on nano-tungsten particles (WC) was synthesized from gel prepared by using nanoparticles of WO3, previously produced from W-powder oxidized in H2O2. The support was porous material with high specific surface area (177 m2 g−1).The WC supported Pt (10 wt.%) catalyst was prepared by borohydride reduction method.X-ray diffraction of the catalyst demonstrates successful reduction of Pt precursor to metallic form. STEM analysis of Pt/WC catalyst showed the existence of Pt particles lower than 2 nm in size, even the clusters of Pt atoms.Electrochemically active surface area of Pt was determined from adsorption/desorption charge of hydrogen atoms.Catalytic activity of the synthesized catalyst for ORR was studied by cyclic voltammetry and linear sweep voltammetry at rotating disk electrode. The onset potential on Pt/WC for ORR, comparing with Pt/Vulcan, was shifted to the positive potentials for about 150 mV. Pt/WC catalyst shows one Tafel slope of −0.105 V dec−1, remarkable catalytic activity expressed either through the value of the current density per real surface area, or through the mass activity and excellent stability.
PB  - Elsevier
T2  - Electrochimica Acta
T1  - Pt supported on nano-tungsten carbide as a beneficial catalyst for the oxygen reduction reaction in alkaline solution
EP  - 246
SP  - 239
VL  - 69
DO  - 10.1016/j.electacta.2012.02.105
UR  - https://hdl.handle.net/21.15107/rcub_dais_465
ER  - 

@article{
author = "Elezović, Nevenka and Babić, Biljana M. and Gajić Krstajić, Ljiljana and Ercius, Peter and Radmilović, Velimir R. and Krstajić, Nedeljko and Vračar, Ljiljana",
year = "2012",
abstract = "Platinum nanocatalyst at nano-tungsten carbide was synthesized, characterized and tested for oxygen reduction reaction (ORR) in 0.1 mol dm−3 NaOH, at 25 °C. Tungsten-carbide islands on nano-tungsten particles (WC) was synthesized from gel prepared by using nanoparticles of WO3, previously produced from W-powder oxidized in H2O2. The support was porous material with high specific surface area (177 m2 g−1).The WC supported Pt (10 wt.%) catalyst was prepared by borohydride reduction method.X-ray diffraction of the catalyst demonstrates successful reduction of Pt precursor to metallic form. STEM analysis of Pt/WC catalyst showed the existence of Pt particles lower than 2 nm in size, even the clusters of Pt atoms.Electrochemically active surface area of Pt was determined from adsorption/desorption charge of hydrogen atoms.Catalytic activity of the synthesized catalyst for ORR was studied by cyclic voltammetry and linear sweep voltammetry at rotating disk electrode. The onset potential on Pt/WC for ORR, comparing with Pt/Vulcan, was shifted to the positive potentials for about 150 mV. Pt/WC catalyst shows one Tafel slope of −0.105 V dec−1, remarkable catalytic activity expressed either through the value of the current density per real surface area, or through the mass activity and excellent stability.",
publisher = "Elsevier",
journal = "Electrochimica Acta",
title = "Pt supported on nano-tungsten carbide as a beneficial catalyst for the oxygen reduction reaction in alkaline solution",
pages = "246-239",
volume = "69",
doi = "10.1016/j.electacta.2012.02.105",
url = "https://hdl.handle.net/21.15107/rcub_dais_465"
}

Elezović, N., Babić, B. M., Gajić Krstajić, L., Ercius, P., Radmilović, V. R., Krstajić, N.,& Vračar, L.. (2012). Pt supported on nano-tungsten carbide as a beneficial catalyst for the oxygen reduction reaction in alkaline solution. in Electrochimica Acta
Elsevier., 69, 239-246.
https://doi.org/10.1016/j.electacta.2012.02.105
https://hdl.handle.net/21.15107/rcub_dais_465

Elezović N, Babić BM, Gajić Krstajić L, Ercius P, Radmilović VR, Krstajić N, Vračar L. Pt supported on nano-tungsten carbide as a beneficial catalyst for the oxygen reduction reaction in alkaline solution. in Electrochimica Acta. 2012;69:239-246.
doi:10.1016/j.electacta.2012.02.105
https://hdl.handle.net/21.15107/rcub_dais_465 .

Elezović, Nevenka, Babić, Biljana M., Gajić Krstajić, Ljiljana, Ercius, Peter, Radmilović, Velimir R., Krstajić, Nedeljko, Vračar, Ljiljana, "Pt supported on nano-tungsten carbide as a beneficial catalyst for the oxygen reduction reaction in alkaline solution" in Electrochimica Acta, 69 (2012):239-246,
https://doi.org/10.1016/j.electacta.2012.02.105 .,
https://hdl.handle.net/21.15107/rcub_dais_465 .

TY  - JOUR
AU  - Obradović, Maja
AU  - Gojković, Snežana Lj.
AU  - Elezović, Nevenka R.
AU  - Ercius, P.
AU  - Radmilović, Velimir R.
AU  - Vračar, Ljiljana M.
AU  - Krstajić, Nedeljko V.
PY  - 2012
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/2127
AB  - The catalytic activity of WC/Pt electrocatalysts towards hydrogen oxidation reaction (HOR) in acid solution was studied. Tungsten carbide (WC) prepared by polycondensation of resorcinol and formaldehyde in the presence of ammonium metatungstate salt and CTABr surfactant was used as the support of a Pt electrocatalyst (WC/Pt). The obtained WC/Pt electrodes were characterized by XRD, HRTEM, EDS, EELS and electrochemical measurements. HRTEM analysis showed that the WC particles possess a core-shell structure with a metallic tungsten core and a shell composed of a mixture of tungsten carbides shell (WC and W2C). The WC/Pt catalyst is composed of well-dispersed sub-nanometer Pt clusters which consist of a few to several tens of Pt atoms. EELS measurements indicate that the WC particles function as nucleation sites for Pt nanoparticles. Based on the Tafel-Heyrovsky-Volmer mechanism the corresponding kinetic equations were derived to describe the HOR current-potential behavior over the entire potential region on RDE. The fitting showed that in the lower potential region HOR on Pt proceeds most likely via the Tafel-Volmer (TV) pathway. The kinetic results also showed that the WC/Pt(1%) when compared to the standard C/Pt(1%) electrode led to a remarkable enhancement of the hydrogen oxidation in an acidic medium, which was explained by H-spill-over between platinum and tungsten carbide.
PB  - Elsevier Science Sa, Lausanne
T2  - Journal of Electroanalytical Chemistry
T1  - The kinetics of the hydrogen oxidation reaction on WC/Pt catalyst with low content of Pt nano-particles
EP  - 32
SP  - 24
VL  - 671
DO  - 10.1016/j.jelechem.2012.01.026
ER  - 

@article{
author = "Obradović, Maja and Gojković, Snežana Lj. and Elezović, Nevenka R. and Ercius, P. and Radmilović, Velimir R. and Vračar, Ljiljana M. and Krstajić, Nedeljko V.",
year = "2012",
abstract = "The catalytic activity of WC/Pt electrocatalysts towards hydrogen oxidation reaction (HOR) in acid solution was studied. Tungsten carbide (WC) prepared by polycondensation of resorcinol and formaldehyde in the presence of ammonium metatungstate salt and CTABr surfactant was used as the support of a Pt electrocatalyst (WC/Pt). The obtained WC/Pt electrodes were characterized by XRD, HRTEM, EDS, EELS and electrochemical measurements. HRTEM analysis showed that the WC particles possess a core-shell structure with a metallic tungsten core and a shell composed of a mixture of tungsten carbides shell (WC and W2C). The WC/Pt catalyst is composed of well-dispersed sub-nanometer Pt clusters which consist of a few to several tens of Pt atoms. EELS measurements indicate that the WC particles function as nucleation sites for Pt nanoparticles. Based on the Tafel-Heyrovsky-Volmer mechanism the corresponding kinetic equations were derived to describe the HOR current-potential behavior over the entire potential region on RDE. The fitting showed that in the lower potential region HOR on Pt proceeds most likely via the Tafel-Volmer (TV) pathway. The kinetic results also showed that the WC/Pt(1%) when compared to the standard C/Pt(1%) electrode led to a remarkable enhancement of the hydrogen oxidation in an acidic medium, which was explained by H-spill-over between platinum and tungsten carbide.",
publisher = "Elsevier Science Sa, Lausanne",
journal = "Journal of Electroanalytical Chemistry",
title = "The kinetics of the hydrogen oxidation reaction on WC/Pt catalyst with low content of Pt nano-particles",
pages = "32-24",
volume = "671",
doi = "10.1016/j.jelechem.2012.01.026"
}

Obradović, M., Gojković, S. Lj., Elezović, N. R., Ercius, P., Radmilović, V. R., Vračar, L. M.,& Krstajić, N. V.. (2012). The kinetics of the hydrogen oxidation reaction on WC/Pt catalyst with low content of Pt nano-particles. in Journal of Electroanalytical Chemistry
Elsevier Science Sa, Lausanne., 671, 24-32.
https://doi.org/10.1016/j.jelechem.2012.01.026

Obradović M, Gojković SL, Elezović NR, Ercius P, Radmilović VR, Vračar LM, Krstajić NV. The kinetics of the hydrogen oxidation reaction on WC/Pt catalyst with low content of Pt nano-particles. in Journal of Electroanalytical Chemistry. 2012;671:24-32.
doi:10.1016/j.jelechem.2012.01.026 .

Obradović, Maja, Gojković, Snežana Lj., Elezović, Nevenka R., Ercius, P., Radmilović, Velimir R., Vračar, Ljiljana M., Krstajić, Nedeljko V., "The kinetics of the hydrogen oxidation reaction on WC/Pt catalyst with low content of Pt nano-particles" in Journal of Electroanalytical Chemistry, 671 (2012):24-32,
https://doi.org/10.1016/j.jelechem.2012.01.026 . .

TY  - JOUR
AU  - Elezović, Nevenka R.
AU  - Babić, Biljana M.
AU  - Gajić Krstajić, Ljiljana
AU  - Radmilović, Velimir R.
AU  - Krstajić, Nedeljko
AU  - Vračar, Ljiljana
PY  - 2010
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/5617
AB  - In order to point out the effect of the support to the catalyst for oxygen reduction reaction nano-crystalline Nb-doped TiO2 was synthesized through a modified sol-gel route procedure. The specific surface area of the support, SBET, and pore size distribution, were calculated from the adsorption isotherms using the gravimetric McBain method. The support was characterized by X-ray diffraction (XRD) technique. The borohydride reduction method was used to prepare Nb-TiO2 supported Pt (20 wt.%) catalyst. The synthesized catalyst was analyzed by TEM technique. Finally, the catalytic activity of this new catalyst for oxygen reduction reaction was investigated in acid solution, in the absence and the presence of methanol, and its activity was compared towards the results on C/Pt catalysts. Kinetic analysis reveals that the oxygen reduction reaction on Nb-TiO2/Pt catalyst follows four-electron process leading to water, as in the case of C/Pt electrode, but the Tafel plots normalized to the electrochemically active surface area show very remarkable enhancement in activity of Nb-TiO2/Pt expressed through the value of the current density at the constant potential. Moreover, Nb-TiO2/Pt catalyst exhibits higher methanol tolerance during the oxygen reduction reaction than the C/Pt catalyst. The enhancement in the activity of Nb-TiO2/Pt is consequence of both: the interactions of Pt nanoparticles with the support and the energy shift of the surface d-states with respect to the Fermi level what changes the surface reactivity. © 2010 Elsevier B.V.
PB  - Elsevier
T2  - Journal of Power Sources
T1  - Synthesis, characterization and electrocatalytical behavior of Nb-TiO2/Pt nanocatalyst for oxygen reduction reaction
EP  - 3968
IS  - 13
SP  - 3961
VL  - 195
DO  - 10.1016/j.jpowsour.2010.01.035
UR  - https://hdl.handle.net/21.15107/rcub_dais_3418
ER  - 

@article{
author = "Elezović, Nevenka R. and Babić, Biljana M. and Gajić Krstajić, Ljiljana and Radmilović, Velimir R. and Krstajić, Nedeljko and Vračar, Ljiljana",
year = "2010",
abstract = "In order to point out the effect of the support to the catalyst for oxygen reduction reaction nano-crystalline Nb-doped TiO2 was synthesized through a modified sol-gel route procedure. The specific surface area of the support, SBET, and pore size distribution, were calculated from the adsorption isotherms using the gravimetric McBain method. The support was characterized by X-ray diffraction (XRD) technique. The borohydride reduction method was used to prepare Nb-TiO2 supported Pt (20 wt.%) catalyst. The synthesized catalyst was analyzed by TEM technique. Finally, the catalytic activity of this new catalyst for oxygen reduction reaction was investigated in acid solution, in the absence and the presence of methanol, and its activity was compared towards the results on C/Pt catalysts. Kinetic analysis reveals that the oxygen reduction reaction on Nb-TiO2/Pt catalyst follows four-electron process leading to water, as in the case of C/Pt electrode, but the Tafel plots normalized to the electrochemically active surface area show very remarkable enhancement in activity of Nb-TiO2/Pt expressed through the value of the current density at the constant potential. Moreover, Nb-TiO2/Pt catalyst exhibits higher methanol tolerance during the oxygen reduction reaction than the C/Pt catalyst. The enhancement in the activity of Nb-TiO2/Pt is consequence of both: the interactions of Pt nanoparticles with the support and the energy shift of the surface d-states with respect to the Fermi level what changes the surface reactivity. © 2010 Elsevier B.V.",
publisher = "Elsevier",
journal = "Journal of Power Sources",
title = "Synthesis, characterization and electrocatalytical behavior of Nb-TiO2/Pt nanocatalyst for oxygen reduction reaction",
pages = "3968-3961",
number = "13",
volume = "195",
doi = "10.1016/j.jpowsour.2010.01.035",
url = "https://hdl.handle.net/21.15107/rcub_dais_3418"
}

Elezović, N. R., Babić, B. M., Gajić Krstajić, L., Radmilović, V. R., Krstajić, N.,& Vračar, L.. (2010). Synthesis, characterization and electrocatalytical behavior of Nb-TiO2/Pt nanocatalyst for oxygen reduction reaction. in Journal of Power Sources
Elsevier., 195(13), 3961-3968.
https://doi.org/10.1016/j.jpowsour.2010.01.035
https://hdl.handle.net/21.15107/rcub_dais_3418

Elezović NR, Babić BM, Gajić Krstajić L, Radmilović VR, Krstajić N, Vračar L. Synthesis, characterization and electrocatalytical behavior of Nb-TiO2/Pt nanocatalyst for oxygen reduction reaction. in Journal of Power Sources. 2010;195(13):3961-3968.
doi:10.1016/j.jpowsour.2010.01.035
https://hdl.handle.net/21.15107/rcub_dais_3418 .

Elezović, Nevenka R., Babić, Biljana M., Gajić Krstajić, Ljiljana, Radmilović, Velimir R., Krstajić, Nedeljko, Vračar, Ljiljana, "Synthesis, characterization and electrocatalytical behavior of Nb-TiO2/Pt nanocatalyst for oxygen reduction reaction" in Journal of Power Sources, 195, no. 13 (2010):3961-3968,
https://doi.org/10.1016/j.jpowsour.2010.01.035 .,
https://hdl.handle.net/21.15107/rcub_dais_3418 .

TY  - JOUR
AU  - Elezović, Nevenka
AU  - Gajić Krstajić, Ljiljana
AU  - Vračar, Ljiljana
AU  - Krstajić, Nedeljko
PY  - 2010
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/5591
AB  - The influence of poisoning of MoOx-Pt catalyst by CO on the kinetics of H2 oxidation reaction (HOR) at MoOx-Pt electrode in 0.5 mol dm-3 HClO4 saturated with H 2 containing 100 ppm CO, was examined on rotating disc electrode (RDE) at 25 °C. MoOx-Pt nano-catalyst prepared by the polyole method combined with MoOx post-deposition was supported on commercial carbon black, Vulcan XC-72. The MoOx-Pt/C catalyst was characterized by TEM technique. The catalyst composition is very similar to the nominal one and post-deposited MoOx species block only a small fraction of the active Pt particle surface area. MoOx deposition on the carbon support can be ruled out from the EDAX results and from the low mobility of these oxides under used conditions. Based on Tafel-Heyrovsky-Volmer mechanism the corresponding kinetic equations from a dual-pathway model were derived to describe oxidation current-potential behavior on RDE over entire potential range, at various CO coverages. The polarization RDE curves were fitted with derived polarization equations according to the proposed model. The fitting showed that the HOR proceeded most likely via the Tafel-Volmer (TV) pathway. A very high electrocatalytic activity observed at MoOx-Pt catalyst for the hydrogen oxidation reaction in the presence of 100 ppm CO is achieved through chemical surface reaction of adsorbed CO with Mo surface oxides. © 2009 Professor T. Nejat Veziroglu. Published by Elsevier Ltd. All rights reserved.
PB  - Elsevier
T2  - International Journal of Hydrogen Energy
T2  - International Journal of Hydrogen Energy
T1  - Effect of chemisorbed CO on MoOx-Pt/C electrode on the kinetics of hydrogen oxidation reaction
EP  - 12887
IS  - 23
SP  - 12878
VL  - 35
DO  - 10.1016/j.ijhydene.2010.09.004
UR  - https://hdl.handle.net/21.15107/rcub_dais_3410
ER  - 

@article{
author = "Elezović, Nevenka and Gajić Krstajić, Ljiljana and Vračar, Ljiljana and Krstajić, Nedeljko",
year = "2010",
abstract = "The influence of poisoning of MoOx-Pt catalyst by CO on the kinetics of H2 oxidation reaction (HOR) at MoOx-Pt electrode in 0.5 mol dm-3 HClO4 saturated with H 2 containing 100 ppm CO, was examined on rotating disc electrode (RDE) at 25 °C. MoOx-Pt nano-catalyst prepared by the polyole method combined with MoOx post-deposition was supported on commercial carbon black, Vulcan XC-72. The MoOx-Pt/C catalyst was characterized by TEM technique. The catalyst composition is very similar to the nominal one and post-deposited MoOx species block only a small fraction of the active Pt particle surface area. MoOx deposition on the carbon support can be ruled out from the EDAX results and from the low mobility of these oxides under used conditions. Based on Tafel-Heyrovsky-Volmer mechanism the corresponding kinetic equations from a dual-pathway model were derived to describe oxidation current-potential behavior on RDE over entire potential range, at various CO coverages. The polarization RDE curves were fitted with derived polarization equations according to the proposed model. The fitting showed that the HOR proceeded most likely via the Tafel-Volmer (TV) pathway. A very high electrocatalytic activity observed at MoOx-Pt catalyst for the hydrogen oxidation reaction in the presence of 100 ppm CO is achieved through chemical surface reaction of adsorbed CO with Mo surface oxides. © 2009 Professor T. Nejat Veziroglu. Published by Elsevier Ltd. All rights reserved.",
publisher = "Elsevier",
journal = "International Journal of Hydrogen Energy, International Journal of Hydrogen Energy",
title = "Effect of chemisorbed CO on MoOx-Pt/C electrode on the kinetics of hydrogen oxidation reaction",
pages = "12887-12878",
number = "23",
volume = "35",
doi = "10.1016/j.ijhydene.2010.09.004",
url = "https://hdl.handle.net/21.15107/rcub_dais_3410"
}

Elezović, N., Gajić Krstajić, L., Vračar, L.,& Krstajić, N.. (2010). Effect of chemisorbed CO on MoOx-Pt/C electrode on the kinetics of hydrogen oxidation reaction. in International Journal of Hydrogen Energy
Elsevier., 35(23), 12878-12887.
https://doi.org/10.1016/j.ijhydene.2010.09.004
https://hdl.handle.net/21.15107/rcub_dais_3410

Elezović N, Gajić Krstajić L, Vračar L, Krstajić N. Effect of chemisorbed CO on MoOx-Pt/C electrode on the kinetics of hydrogen oxidation reaction. in International Journal of Hydrogen Energy. 2010;35(23):12878-12887.
doi:10.1016/j.ijhydene.2010.09.004
https://hdl.handle.net/21.15107/rcub_dais_3410 .

Elezović, Nevenka, Gajić Krstajić, Ljiljana, Vračar, Ljiljana, Krstajić, Nedeljko, "Effect of chemisorbed CO on MoOx-Pt/C electrode on the kinetics of hydrogen oxidation reaction" in International Journal of Hydrogen Energy, 35, no. 23 (2010):12878-12887,
https://doi.org/10.1016/j.ijhydene.2010.09.004 .,
https://hdl.handle.net/21.15107/rcub_dais_3410 .

TY  - JOUR
AU  - Babić, Biljana M.
AU  - Gulicovski, Jelena
AU  - Gajić Krstajić, Ljiljana
AU  - Elezović, Nevenka
AU  - Radmilović, Velimir R.
AU  - Krstajić, Nedeljko
AU  - Vračar, Ljiljana
PY  - 2009
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/5531
AB  - The kinetics and mechanism of the hydrogen oxidation reaction were studied in 0.5 mol dm-3 HClO4 solution on an electrode based on titanium oxide with Magneli phase structure-supported platinum electrocatalyst applied on rotation Au disk electrode. Pt catalyst was prepared by impregnation method from 2-propanol solution of Pt(NH3)2(NO2)2 and sub-stoichiometric titanium oxide powder. Sub-stiochiometric titanium oxide support was characterized by X-ray diffraction and BET techniques. The synthesized catalyst was analyzed by TEM technique. Based on Tafel-Heyrovsky-Volmer mechanism the corresponding kinetic equations were derived to describe the hydrogen oxidation current-potential behavior on RDE over the entire potential region. The polarization RDE curves were fitted with derived polarization equations according to proposed model. The fitting shows that the HOR on Pt proceeds most likely via the Tafel-Volmer (TV) pathway in the lower potential region, while the Heyrovsky-Volmer (HV) pathway is operative in the higher potential region. It is pointed out that Tafel equation that has been frequently used for the kinetics analysis in the HOR, can not reproduce the polarization curves measured with high mass-transport rates. Polarization measurements on RDE revealed that the Pt catalyst deposited on titanium suboxide support showed equal specific activity for the HOR compared to conventional carbon-supported Pt fuel cell catalyst. © 2008 Elsevier B.V. All rights reserved.
PB  - Elsevier
T2  - Journal of Power Sources
T1  - Kinetic study of the hydrogen oxidation reaction on sub-stoichiometric titanium oxide-supported platinum electrocatalyst in acid solution
EP  - 106
IS  - 1
SP  - 99
VL  - 193
DO  - 10.1016/j.jpowsour.2008.11.142
UR  - https://hdl.handle.net/21.15107/rcub_dais_3480
ER  - 

@article{
author = "Babić, Biljana M. and Gulicovski, Jelena and Gajić Krstajić, Ljiljana and Elezović, Nevenka and Radmilović, Velimir R. and Krstajić, Nedeljko and Vračar, Ljiljana",
year = "2009",
abstract = "The kinetics and mechanism of the hydrogen oxidation reaction were studied in 0.5 mol dm-3 HClO4 solution on an electrode based on titanium oxide with Magneli phase structure-supported platinum electrocatalyst applied on rotation Au disk electrode. Pt catalyst was prepared by impregnation method from 2-propanol solution of Pt(NH3)2(NO2)2 and sub-stoichiometric titanium oxide powder. Sub-stiochiometric titanium oxide support was characterized by X-ray diffraction and BET techniques. The synthesized catalyst was analyzed by TEM technique. Based on Tafel-Heyrovsky-Volmer mechanism the corresponding kinetic equations were derived to describe the hydrogen oxidation current-potential behavior on RDE over the entire potential region. The polarization RDE curves were fitted with derived polarization equations according to proposed model. The fitting shows that the HOR on Pt proceeds most likely via the Tafel-Volmer (TV) pathway in the lower potential region, while the Heyrovsky-Volmer (HV) pathway is operative in the higher potential region. It is pointed out that Tafel equation that has been frequently used for the kinetics analysis in the HOR, can not reproduce the polarization curves measured with high mass-transport rates. Polarization measurements on RDE revealed that the Pt catalyst deposited on titanium suboxide support showed equal specific activity for the HOR compared to conventional carbon-supported Pt fuel cell catalyst. © 2008 Elsevier B.V. All rights reserved.",
publisher = "Elsevier",
journal = "Journal of Power Sources",
title = "Kinetic study of the hydrogen oxidation reaction on sub-stoichiometric titanium oxide-supported platinum electrocatalyst in acid solution",
pages = "106-99",
number = "1",
volume = "193",
doi = "10.1016/j.jpowsour.2008.11.142",
url = "https://hdl.handle.net/21.15107/rcub_dais_3480"
}

Babić, B. M., Gulicovski, J., Gajić Krstajić, L., Elezović, N., Radmilović, V. R., Krstajić, N.,& Vračar, L.. (2009). Kinetic study of the hydrogen oxidation reaction on sub-stoichiometric titanium oxide-supported platinum electrocatalyst in acid solution. in Journal of Power Sources
Elsevier., 193(1), 99-106.
https://doi.org/10.1016/j.jpowsour.2008.11.142
https://hdl.handle.net/21.15107/rcub_dais_3480

Babić BM, Gulicovski J, Gajić Krstajić L, Elezović N, Radmilović VR, Krstajić N, Vračar L. Kinetic study of the hydrogen oxidation reaction on sub-stoichiometric titanium oxide-supported platinum electrocatalyst in acid solution. in Journal of Power Sources. 2009;193(1):99-106.
doi:10.1016/j.jpowsour.2008.11.142
https://hdl.handle.net/21.15107/rcub_dais_3480 .

Babić, Biljana M., Gulicovski, Jelena, Gajić Krstajić, Ljiljana, Elezović, Nevenka, Radmilović, Velimir R., Krstajić, Nedeljko, Vračar, Ljiljana, "Kinetic study of the hydrogen oxidation reaction on sub-stoichiometric titanium oxide-supported platinum electrocatalyst in acid solution" in Journal of Power Sources, 193, no. 1 (2009):99-106,
https://doi.org/10.1016/j.jpowsour.2008.11.142 .,
https://hdl.handle.net/21.15107/rcub_dais_3480 .

TY  - JOUR
AU  - Elezović, Nevenka R.
AU  - Gajić Krstajić, Ljiljana
AU  - Radmilović, Velimir R.
AU  - Vračar, Ljiljana
AU  - Krstajić, Nedeljko
PY  - 2009
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/5525
AB  - The influence of poisoning of Pt catalyst by CO on the kinetics and mechanism of H2 oxidation reaction (HOR) at Pt/C electrode in 0.5 mol dm-3 HClO4, saturated with H2 containing 100 ppm CO, was examined with rotating disc electrode (RDE) at 22 °C. Commercial carbon black, Vulcan XC-72 was used as support, while Pt/C catalyst was prepared by modified polyol synthesis method in an ethylene glycol (EG) solution. The kinetically controlled current (Ik) for the HOR at Pt/C decreases significantly at CO coverage (ΘCO) > 0.6. For ΘCO < 0.6 the HOR takes place through Tafel-Volmer mechanism with Tafel reaction as rate-determining step at the low CO coverage, while Volmer step controls the overall reaction rate at the medium CO coverage. When CO coverage is higher then 0.6, Heyrovsky-Volmer mechanism is operative for the HOR with Heyrovsky as the rate-determining step (rds). © 2008 Elsevier Ltd. All rights reserved.
PB  - Elsevier
T2  - Electrochimica Acta
T1  - Effect of chemisorbed carbon monoxide on Pt/C electrode on the mechanism of the hydrogen oxidation reaction
EP  - 1382
IS  - 4
SP  - 1375
VL  - 54
DO  - 10.1016/j.electacta.2008.08.067
UR  - https://hdl.handle.net/21.15107/rcub_dais_3485
ER  - 

@article{
author = "Elezović, Nevenka R. and Gajić Krstajić, Ljiljana and Radmilović, Velimir R. and Vračar, Ljiljana and Krstajić, Nedeljko",
year = "2009",
abstract = "The influence of poisoning of Pt catalyst by CO on the kinetics and mechanism of H2 oxidation reaction (HOR) at Pt/C electrode in 0.5 mol dm-3 HClO4, saturated with H2 containing 100 ppm CO, was examined with rotating disc electrode (RDE) at 22 °C. Commercial carbon black, Vulcan XC-72 was used as support, while Pt/C catalyst was prepared by modified polyol synthesis method in an ethylene glycol (EG) solution. The kinetically controlled current (Ik) for the HOR at Pt/C decreases significantly at CO coverage (ΘCO) > 0.6. For ΘCO < 0.6 the HOR takes place through Tafel-Volmer mechanism with Tafel reaction as rate-determining step at the low CO coverage, while Volmer step controls the overall reaction rate at the medium CO coverage. When CO coverage is higher then 0.6, Heyrovsky-Volmer mechanism is operative for the HOR with Heyrovsky as the rate-determining step (rds). © 2008 Elsevier Ltd. All rights reserved.",
publisher = "Elsevier",
journal = "Electrochimica Acta",
title = "Effect of chemisorbed carbon monoxide on Pt/C electrode on the mechanism of the hydrogen oxidation reaction",
pages = "1382-1375",
number = "4",
volume = "54",
doi = "10.1016/j.electacta.2008.08.067",
url = "https://hdl.handle.net/21.15107/rcub_dais_3485"
}

Elezović, N. R., Gajić Krstajić, L., Radmilović, V. R., Vračar, L.,& Krstajić, N.. (2009). Effect of chemisorbed carbon monoxide on Pt/C electrode on the mechanism of the hydrogen oxidation reaction. in Electrochimica Acta
Elsevier., 54(4), 1375-1382.
https://doi.org/10.1016/j.electacta.2008.08.067
https://hdl.handle.net/21.15107/rcub_dais_3485

Elezović NR, Gajić Krstajić L, Radmilović VR, Vračar L, Krstajić N. Effect of chemisorbed carbon monoxide on Pt/C electrode on the mechanism of the hydrogen oxidation reaction. in Electrochimica Acta. 2009;54(4):1375-1382.
doi:10.1016/j.electacta.2008.08.067
https://hdl.handle.net/21.15107/rcub_dais_3485 .

Elezović, Nevenka R., Gajić Krstajić, Ljiljana, Radmilović, Velimir R., Vračar, Ljiljana, Krstajić, Nedeljko, "Effect of chemisorbed carbon monoxide on Pt/C electrode on the mechanism of the hydrogen oxidation reaction" in Electrochimica Acta, 54, no. 4 (2009):1375-1382,
https://doi.org/10.1016/j.electacta.2008.08.067 .,
https://hdl.handle.net/21.15107/rcub_dais_3485 .

TY  - JOUR
AU  - Elezović, Nevenka R.
AU  - Babić, Biljana M.
AU  - Radmilović, Velimir R.
AU  - Gojković, Snežana Lj.
AU  - Krstajić, Nedeljko V.
AU  - Vračar, Ljiljana M.
PY  - 2008
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/1282
AB  - The oxidation of methanol and reduction of oxygen were studied on MoOx-Pt/C nano-catalysts prepared by the polyole method combined by MoOx post-deposition. The catalysts were characterized by TEM and EDX. The presented composition of the electrode is very similar to the nominal ones and post-deposited MoOx species block only a small fraction of the active Pt particle surface area. MoOx deposition on the carbon support can be ruled out from the EDX results and the low mobility of these oxides at corresponding conditions. The electrode catalytic activity in the electrooxidation of methanol and the reduction of oxygen was studied by steady-state voltammetry and cyclic voltammetry. MoOx-Pt/C catalyst exhibits higher catalytic activity than Pt/C for the oxygen reduction. The catalytic effect in oxidation of methanol is achieved only under potentiodynamic conditions, when poisoning species have no enough time to develop fully.
PB  - Elsevier Science Bv, Amsterdam
T2  - Journal of Power Sources
T1  - Pt/C doped by MoOx as the electrocatalyst for oxygen reduction and methanol oxidation
EP  - 255
IS  - 1
SP  - 250
VL  - 175
DO  - 10.1016/j.jpowsour.2007.09.011
ER  - 

@article{
author = "Elezović, Nevenka R. and Babić, Biljana M. and Radmilović, Velimir R. and Gojković, Snežana Lj. and Krstajić, Nedeljko V. and Vračar, Ljiljana M.",
year = "2008",
abstract = "The oxidation of methanol and reduction of oxygen were studied on MoOx-Pt/C nano-catalysts prepared by the polyole method combined by MoOx post-deposition. The catalysts were characterized by TEM and EDX. The presented composition of the electrode is very similar to the nominal ones and post-deposited MoOx species block only a small fraction of the active Pt particle surface area. MoOx deposition on the carbon support can be ruled out from the EDX results and the low mobility of these oxides at corresponding conditions. The electrode catalytic activity in the electrooxidation of methanol and the reduction of oxygen was studied by steady-state voltammetry and cyclic voltammetry. MoOx-Pt/C catalyst exhibits higher catalytic activity than Pt/C for the oxygen reduction. The catalytic effect in oxidation of methanol is achieved only under potentiodynamic conditions, when poisoning species have no enough time to develop fully.",
publisher = "Elsevier Science Bv, Amsterdam",
journal = "Journal of Power Sources",
title = "Pt/C doped by MoOx as the electrocatalyst for oxygen reduction and methanol oxidation",
pages = "255-250",
number = "1",
volume = "175",
doi = "10.1016/j.jpowsour.2007.09.011"
}

Elezović, N. R., Babić, B. M., Radmilović, V. R., Gojković, S. Lj., Krstajić, N. V.,& Vračar, L. M.. (2008). Pt/C doped by MoOx as the electrocatalyst for oxygen reduction and methanol oxidation. in Journal of Power Sources
Elsevier Science Bv, Amsterdam., 175(1), 250-255.
https://doi.org/10.1016/j.jpowsour.2007.09.011

Elezović NR, Babić BM, Radmilović VR, Gojković SL, Krstajić NV, Vračar LM. Pt/C doped by MoOx as the electrocatalyst for oxygen reduction and methanol oxidation. in Journal of Power Sources. 2008;175(1):250-255.
doi:10.1016/j.jpowsour.2007.09.011 .

Elezović, Nevenka R., Babić, Biljana M., Radmilović, Velimir R., Gojković, Snežana Lj., Krstajić, Nedeljko V., Vračar, Ljiljana M., "Pt/C doped by MoOx as the electrocatalyst for oxygen reduction and methanol oxidation" in Journal of Power Sources, 175, no. 1 (2008):250-255,
https://doi.org/10.1016/j.jpowsour.2007.09.011 . .

TY  - JOUR
AU  - Elezović, Nevenka R.
AU  - Babić, Biljana M.
AU  - Krstajić, Nedeljko V.
AU  - Gojković, Snežana Lj.
AU  - Vračar, Ljiljana M.
PY  - 2008
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/1346
AB  - The temperature dependence of oxygen reduction reaction (ORR) was studied on highly dispersed Pt nanoparticles supported on a carbon cryo-gel. The specific surface area of the support was 517 m2 g-1, the Pt particles diameter was about 2.7 nm and the loading of the catalyst was 20 wt.%. The kinetics of the ORR at the Pt/C electrode was examined in 0.50 mol dm-3 HClO4 solution in the temperature range from 274 to 318 K. At all temperatures, two distinct E-log j regions were observed; at low current densities with a slope of -2.3RT/F and at high current densities with a slope of -2.3´2RT/F. In order to confirm the mechanism of oxygen reduction previously suggested at a polycrystalline Pt and a Pt/Ebonex nanostructured electrode, the apparent enthalpies of activation at selected potentials vs. the reversible hydrogen electrode were calculated in both current density regions. Although ∆H ≠a,1  gt  ∆H ≠a,h , it was a,1 a, h found that the enthalpies of activation at the zero Galvani potential difference were the same and hence it could be concluded that the rate-determining step of the ORR was the same in both current density regions. The synthesized Pt/C catalyst showed a small enhancement in the catalytic activity for ORR in comparison to the polycrystalline Pt, but no change in the mechanism of the reaction.
AB  - Kinetika reakcije redukcije kiseonika je ispitivana na nanočesticama platine dispergovanim na ugljeničnom nosaču, u 0,50 mol dm-3 HClO4, u temperaturnom intervalu od 278 do 318 K. Za sintezu Pt katalizatora (Pt/C) je primenjena modifikovana poliol metoda iz rastvora etilen glikola, dok je kao nosač korišćen ugljenični kriogel. Katalizator je okarakterisan primenom BET metode, difrakcije X-zraka (XRD) i transmisione elektronske mikroskopije (TEM). Kinetika reakcije redukcije kiseonika ispitivana je korišćenjem stacionarne polarizacione metode i metode ciklične voltametrije. Oblast malih gustina struje, na svim teperaturama, na krivoj polarizacije, karakteriše vrednost Tafelovog nagiba od -2.3RT/F, dok je u oblasti visokih gustina struje vrednost ovog nagiba -2.3x2RT/F. Određene su vrednosti prividne entalpije aktivacije na konstantnim potencijalima, za obe oblasti gustina struja, i njihova razlika iskazana za nulu Galvanijeve razlike potencijala. Potvrđeno je da je mehanizam redukcije kiseonika, kao i stupanj koji određuje ukupnu brzinu reakcije isti u obe oblasti gustina struja, a da je razlika u kinetici reakcije posledica razlike u zavisnosti adsorpcije reakcionih intermedijara od potencijala. Poređenjem katalitičke aktivnosti, izražene preko gustine struje po realnoj površini katalizatora, konstatovana je nešto veća aktivnost Pt/C katalizatora u odnosu na polikristalnu Pt.
PB  - Serbian Chemical Society, Belgrade
T2  - Journal of the Serbian Chemical Society
T1  - Temperature dependence of the kinetics of oxygen reduction on carbon-supported pt nanoparticles
T1  - Temperaturna zavisnost elektrohemijske redukcije kiseonika na nanočesticama platine na ugljeničnom nosaču
EP  - 654
IS  - 6
SP  - 641
VL  - 73
UR  - https://hdl.handle.net/21.15107/rcub_technorep_1346
ER  - 

@article{
author = "Elezović, Nevenka R. and Babić, Biljana M. and Krstajić, Nedeljko V. and Gojković, Snežana Lj. and Vračar, Ljiljana M.",
year = "2008",
abstract = "The temperature dependence of oxygen reduction reaction (ORR) was studied on highly dispersed Pt nanoparticles supported on a carbon cryo-gel. The specific surface area of the support was 517 m2 g-1, the Pt particles diameter was about 2.7 nm and the loading of the catalyst was 20 wt.%. The kinetics of the ORR at the Pt/C electrode was examined in 0.50 mol dm-3 HClO4 solution in the temperature range from 274 to 318 K. At all temperatures, two distinct E-log j regions were observed; at low current densities with a slope of -2.3RT/F and at high current densities with a slope of -2.3´2RT/F. In order to confirm the mechanism of oxygen reduction previously suggested at a polycrystalline Pt and a Pt/Ebonex nanostructured electrode, the apparent enthalpies of activation at selected potentials vs. the reversible hydrogen electrode were calculated in both current density regions. Although ∆H ≠a,1  gt  ∆H ≠a,h , it was a,1 a, h found that the enthalpies of activation at the zero Galvani potential difference were the same and hence it could be concluded that the rate-determining step of the ORR was the same in both current density regions. The synthesized Pt/C catalyst showed a small enhancement in the catalytic activity for ORR in comparison to the polycrystalline Pt, but no change in the mechanism of the reaction., Kinetika reakcije redukcije kiseonika je ispitivana na nanočesticama platine dispergovanim na ugljeničnom nosaču, u 0,50 mol dm-3 HClO4, u temperaturnom intervalu od 278 do 318 K. Za sintezu Pt katalizatora (Pt/C) je primenjena modifikovana poliol metoda iz rastvora etilen glikola, dok je kao nosač korišćen ugljenični kriogel. Katalizator je okarakterisan primenom BET metode, difrakcije X-zraka (XRD) i transmisione elektronske mikroskopije (TEM). Kinetika reakcije redukcije kiseonika ispitivana je korišćenjem stacionarne polarizacione metode i metode ciklične voltametrije. Oblast malih gustina struje, na svim teperaturama, na krivoj polarizacije, karakteriše vrednost Tafelovog nagiba od -2.3RT/F, dok je u oblasti visokih gustina struje vrednost ovog nagiba -2.3x2RT/F. Određene su vrednosti prividne entalpije aktivacije na konstantnim potencijalima, za obe oblasti gustina struja, i njihova razlika iskazana za nulu Galvanijeve razlike potencijala. Potvrđeno je da je mehanizam redukcije kiseonika, kao i stupanj koji određuje ukupnu brzinu reakcije isti u obe oblasti gustina struja, a da je razlika u kinetici reakcije posledica razlike u zavisnosti adsorpcije reakcionih intermedijara od potencijala. Poređenjem katalitičke aktivnosti, izražene preko gustine struje po realnoj površini katalizatora, konstatovana je nešto veća aktivnost Pt/C katalizatora u odnosu na polikristalnu Pt.",
publisher = "Serbian Chemical Society, Belgrade",
journal = "Journal of the Serbian Chemical Society",
title = "Temperature dependence of the kinetics of oxygen reduction on carbon-supported pt nanoparticles, Temperaturna zavisnost elektrohemijske redukcije kiseonika na nanočesticama platine na ugljeničnom nosaču",
pages = "654-641",
number = "6",
volume = "73",
url = "https://hdl.handle.net/21.15107/rcub_technorep_1346"
}

Elezović, N. R., Babić, B. M., Krstajić, N. V., Gojković, S. Lj.,& Vračar, L. M.. (2008). Temperature dependence of the kinetics of oxygen reduction on carbon-supported pt nanoparticles. in Journal of the Serbian Chemical Society
Serbian Chemical Society, Belgrade., 73(6), 641-654.
https://hdl.handle.net/21.15107/rcub_technorep_1346

Elezović NR, Babić BM, Krstajić NV, Gojković SL, Vračar LM. Temperature dependence of the kinetics of oxygen reduction on carbon-supported pt nanoparticles. in Journal of the Serbian Chemical Society. 2008;73(6):641-654.
https://hdl.handle.net/21.15107/rcub_technorep_1346 .

Elezović, Nevenka R., Babić, Biljana M., Krstajić, Nedeljko V., Gojković, Snežana Lj., Vračar, Ljiljana M., "Temperature dependence of the kinetics of oxygen reduction on carbon-supported pt nanoparticles" in Journal of the Serbian Chemical Society, 73, no. 6 (2008):641-654,
https://hdl.handle.net/21.15107/rcub_technorep_1346 .

TY  - JOUR
AU  - Babić, Biljana M.
AU  - Kaluđerović, Branka V.
AU  - Vračar, Ljiljana M.
AU  - Radmilovic, Velimir
AU  - Krstajic, Nedeljko V.
PY  - 2007
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/5484
AB  - A carbon cryogel, synthesized by carbonization of a resorcinol/formaldehyde cryogel and oxidized in nitric acid, was used as catalyst Support for Pt nanoparticles. The Pt/C catalyst was prepared by a modified polyol synthesis method in an ethylene glycol (EG) solution. Characterization by nitrogen adsorption showed that the carbon cryogel support and the Pt/C catalyst were mesoporous materials with high specific surface areas (S-BET GT 400 m(2) g(-1)) and large mesoporous Volumes. X-Ray diffraction of the catalyst demonstrated the successful reduction of the Pt precursor to metallic form. TEM Images of the Pt/C catalyst and Pt particle size distribution showed that the mean Pt particle size was about 3.3 nm. Cyclic voltammetry (CV) experiments at various scan rates (from 2 to 200 mV s(-1)) were pet-formed in 0.5 mol dm(-3) HCIO4 solution. The large capacitance of the oxidized carbon cryogel electrode, which arises from a combination of the double-layer capacitance and pseudocapacitance, associated with the participation of surface redox-type reactions was demonstrated. For the oxidized carbon cryogel, the total specific capacitance determined by I1/C vs. v(0.5) extrapolation method was found to be 386 F g-l. The hydrogen oxidation reaction at the investigated Pt/C catalyst proceeded as an electrochemically reversible, two-electron direct discharge reaction.
T2  - Journal of the Serbian Chemical Society
T1  - Characterization of a surface modified carbon cryogel and a carbon supported Pt catalyst
EP  - 785
IS  - 8-9
SP  - 773
VL  - 72
DO  - 10.2298/JSC0709773B
ER  - 

@article{
author = "Babić, Biljana M. and Kaluđerović, Branka V. and Vračar, Ljiljana M. and Radmilovic, Velimir and Krstajic, Nedeljko V.",
year = "2007",
abstract = "A carbon cryogel, synthesized by carbonization of a resorcinol/formaldehyde cryogel and oxidized in nitric acid, was used as catalyst Support for Pt nanoparticles. The Pt/C catalyst was prepared by a modified polyol synthesis method in an ethylene glycol (EG) solution. Characterization by nitrogen adsorption showed that the carbon cryogel support and the Pt/C catalyst were mesoporous materials with high specific surface areas (S-BET GT 400 m(2) g(-1)) and large mesoporous Volumes. X-Ray diffraction of the catalyst demonstrated the successful reduction of the Pt precursor to metallic form. TEM Images of the Pt/C catalyst and Pt particle size distribution showed that the mean Pt particle size was about 3.3 nm. Cyclic voltammetry (CV) experiments at various scan rates (from 2 to 200 mV s(-1)) were pet-formed in 0.5 mol dm(-3) HCIO4 solution. The large capacitance of the oxidized carbon cryogel electrode, which arises from a combination of the double-layer capacitance and pseudocapacitance, associated with the participation of surface redox-type reactions was demonstrated. For the oxidized carbon cryogel, the total specific capacitance determined by I1/C vs. v(0.5) extrapolation method was found to be 386 F g-l. The hydrogen oxidation reaction at the investigated Pt/C catalyst proceeded as an electrochemically reversible, two-electron direct discharge reaction.",
journal = "Journal of the Serbian Chemical Society",
title = "Characterization of a surface modified carbon cryogel and a carbon supported Pt catalyst",
pages = "785-773",
number = "8-9",
volume = "72",
doi = "10.2298/JSC0709773B"
}

Babić, B. M., Kaluđerović, B. V., Vračar, L. M., Radmilovic, V.,& Krstajic, N. V.. (2007). Characterization of a surface modified carbon cryogel and a carbon supported Pt catalyst. in Journal of the Serbian Chemical Society, 72(8-9), 773-785.
https://doi.org/10.2298/JSC0709773B

Babić BM, Kaluđerović BV, Vračar LM, Radmilovic V, Krstajic NV. Characterization of a surface modified carbon cryogel and a carbon supported Pt catalyst. in Journal of the Serbian Chemical Society. 2007;72(8-9):773-785.
doi:10.2298/JSC0709773B .

Babić, Biljana M., Kaluđerović, Branka V., Vračar, Ljiljana M., Radmilovic, Velimir, Krstajic, Nedeljko V., "Characterization of a surface modified carbon cryogel and a carbon supported Pt catalyst" in Journal of the Serbian Chemical Society, 72, no. 8-9 (2007):773-785,
https://doi.org/10.2298/JSC0709773B . .

TY  - JOUR
AU  - Krstajić, Nedeljko V.
AU  - Vračar, Ljiljana M.
AU  - Radmilović, Velimir R.
AU  - Neophytides, Stelios G.
AU  - Labou, Miranda
AU  - Jakšić, Jelena M.
AU  - Tunold, Reidar
AU  - Falaras, Polycarpos
AU  - Jakšić, Milan M.
PY  - 2007
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/5478
AB  - Magneli phases [A. Magneli, Acta Chem. Scand. 13 (1959) 5] have been introduced as a unique electron conductive and interactive support for electrocatalysis both in hydrogen (HELR) and oxygen (OELR) electrode reactions in water electrolysis and Low Temperature PEM Fuel Cells (LT PEM FC). The Strong Metal-Support Interaction (SMSI) that imposes the former implies: (i) the hypo-hyper-d-interbonding effect and its catalytic consequences, and (ii) the interactive primary oxide (M-OH) spillover from the hypo-d-oxide support as a dynamic electrocatalytic contribution. The stronger the bonding, the more strained appear d-orbitals, thereby the less strong the intermediate adsorptive strength in the rate determining step (RDS), and consequently, the faster the facilitated catalytic electrode reaction arises. At the same time the primary oxide spillover transferred from the hypo-d-oxide support directly interferes and reacts either individually and directly to contribute to finish the oxygen reduction, or with other interactive species, like CO to contribute to the CO tolerance. In such a respect, the conditions to provide Au to act as the reversible hydrogen electrode have been proved either by its potentiodynamic surface reconstruction in a heavy water solution, or by the nanostructured SMSI Au on anatase titania with characteristic strained d-orbitals in such a hypo-hyper-d-interactive bonding (Au/TiO2). In the same context, some spontaneous tendency towards monoatomic network dispersion of Pt upon Magneli phases makes it possible to produce an advanced interactive supported electrocatalyst for cathodic oxygen reduction (ORR). The strained hypo-hyper-d-interelectronic and inter-d-orbital metal/hypo-d-oxide support bonding relative to the strength of the latter, has been inferred to be the basis of the synergistic electrocatalytic effect both in the HELR and ORR.
PB  - Elsevier
T2  - Surface Science
T1  - Advances in interactive supported electrocatalysts for hydrogen and oxygen electrode reactions
EP  - 1966
IS  - 9
SP  - 1949
VL  - 601
DO  - 10.1016/j.susc.2007.02.019
ER  - 

@article{
author = "Krstajić, Nedeljko V. and Vračar, Ljiljana M. and Radmilović, Velimir R. and Neophytides, Stelios G. and Labou, Miranda and Jakšić, Jelena M. and Tunold, Reidar and Falaras, Polycarpos and Jakšić, Milan M.",
year = "2007",
abstract = "Magneli phases [A. Magneli, Acta Chem. Scand. 13 (1959) 5] have been introduced as a unique electron conductive and interactive support for electrocatalysis both in hydrogen (HELR) and oxygen (OELR) electrode reactions in water electrolysis and Low Temperature PEM Fuel Cells (LT PEM FC). The Strong Metal-Support Interaction (SMSI) that imposes the former implies: (i) the hypo-hyper-d-interbonding effect and its catalytic consequences, and (ii) the interactive primary oxide (M-OH) spillover from the hypo-d-oxide support as a dynamic electrocatalytic contribution. The stronger the bonding, the more strained appear d-orbitals, thereby the less strong the intermediate adsorptive strength in the rate determining step (RDS), and consequently, the faster the facilitated catalytic electrode reaction arises. At the same time the primary oxide spillover transferred from the hypo-d-oxide support directly interferes and reacts either individually and directly to contribute to finish the oxygen reduction, or with other interactive species, like CO to contribute to the CO tolerance. In such a respect, the conditions to provide Au to act as the reversible hydrogen electrode have been proved either by its potentiodynamic surface reconstruction in a heavy water solution, or by the nanostructured SMSI Au on anatase titania with characteristic strained d-orbitals in such a hypo-hyper-d-interactive bonding (Au/TiO2). In the same context, some spontaneous tendency towards monoatomic network dispersion of Pt upon Magneli phases makes it possible to produce an advanced interactive supported electrocatalyst for cathodic oxygen reduction (ORR). The strained hypo-hyper-d-interelectronic and inter-d-orbital metal/hypo-d-oxide support bonding relative to the strength of the latter, has been inferred to be the basis of the synergistic electrocatalytic effect both in the HELR and ORR.",
publisher = "Elsevier",
journal = "Surface Science",
title = "Advances in interactive supported electrocatalysts for hydrogen and oxygen electrode reactions",
pages = "1966-1949",
number = "9",
volume = "601",
doi = "10.1016/j.susc.2007.02.019"
}

Krstajić, N. V., Vračar, L. M., Radmilović, V. R., Neophytides, S. G., Labou, M., Jakšić, J. M., Tunold, R., Falaras, P.,& Jakšić, M. M.. (2007). Advances in interactive supported electrocatalysts for hydrogen and oxygen electrode reactions. in Surface Science
Elsevier., 601(9), 1949-1966.
https://doi.org/10.1016/j.susc.2007.02.019

Krstajić NV, Vračar LM, Radmilović VR, Neophytides SG, Labou M, Jakšić JM, Tunold R, Falaras P, Jakšić MM. Advances in interactive supported electrocatalysts for hydrogen and oxygen electrode reactions. in Surface Science. 2007;601(9):1949-1966.
doi:10.1016/j.susc.2007.02.019 .

Krstajić, Nedeljko V., Vračar, Ljiljana M., Radmilović, Velimir R., Neophytides, Stelios G., Labou, Miranda, Jakšić, Jelena M., Tunold, Reidar, Falaras, Polycarpos, Jakšić, Milan M., "Advances in interactive supported electrocatalysts for hydrogen and oxygen electrode reactions" in Surface Science, 601, no. 9 (2007):1949-1966,
https://doi.org/10.1016/j.susc.2007.02.019 . .

TY  - JOUR
AU  - Elezović, Nevenka
AU  - Babić, Biljana M.
AU  - Krstajić, Nedeljko
AU  - Gajić Krstajić, Ljiljana
AU  - Vračar, Ljiljana
PY  - 2007
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/5497
AB  - Home-made carbon cryogel synthesized by sol-gel polycondensation and freeze-drying is used as support for preparation of highly dispersed Pt catalyst that is made by a modified polyol synthesis method in an ethylene glycol (EG) solution. Specific surface area of carbon support and Pt/C catalyst is determined from nitrogen adsorption isotherm. The adsorption isotherm demonstrates a significant mesoporosity of carbon support. Specific surface area of the carbon support, calculated by the BET equation, is found to be 573 m(2) g(-1). X-ray diffraction (XRD) results demonstrate a successful reduction of the Pt precursor to its metallic form, and transmission electron microscopy (TEM) images show very uniform Pt particle size distribution with mean particle size of about 2.7 +/- 0.7 nm of the catalyst. Potentiodynamic studies of the underpotential deposition of hydrogen (H-upd) on Pt/C electrode in 0.5 mol dm(-3) HClO4 aqueous solution in the temperature range from 274 to 318 K are made, and thermodynamic state functions for the hydrogen adsorption are determined. The experimental results are analyzed assuming linear variation of the Gibbs energy of adsorption versus theta H-upd on the basis of the surface heterogeneity. The increase of Delta G(Hupd)(theta) with the surface coverage indicates the repulsive interactions between H-upd adatoms. From the temperature dependence of the Gibbs energy of adsorption, the enthalpy and the entropy of adsorption are calculated. The values of these functions are determined to be Delta H-Hupd(theta=0) = -5.6 kJ mol(-1) and Delta S-Hupd(theta=0) = 69.1 J mol(-1) K-1 The value of Delta H-Hupd(theta) allows determinations of the bond energy between electrode surface and H-upd that is found to be Ept-H = 223 kJ mol(-1) for theta = 0.
PB  - Pergamon-Elsevier Science Ltd, Oxford
T2  - International Journal of Hydrogen Energy
T1  - Specificity of the UPD of H to the structure of highly dispersed Pt on carbon support
EP  - 1998
IS  - 12
SP  - 1991
VL  - 32
DO  - 10.1016/j.ijhydene.2006.09.042
UR  - https://hdl.handle.net/21.15107/rcub_dais_12884
ER  - 

@article{
author = "Elezović, Nevenka and Babić, Biljana M. and Krstajić, Nedeljko and Gajić Krstajić, Ljiljana and Vračar, Ljiljana",
year = "2007",
abstract = "Home-made carbon cryogel synthesized by sol-gel polycondensation and freeze-drying is used as support for preparation of highly dispersed Pt catalyst that is made by a modified polyol synthesis method in an ethylene glycol (EG) solution. Specific surface area of carbon support and Pt/C catalyst is determined from nitrogen adsorption isotherm. The adsorption isotherm demonstrates a significant mesoporosity of carbon support. Specific surface area of the carbon support, calculated by the BET equation, is found to be 573 m(2) g(-1). X-ray diffraction (XRD) results demonstrate a successful reduction of the Pt precursor to its metallic form, and transmission electron microscopy (TEM) images show very uniform Pt particle size distribution with mean particle size of about 2.7 +/- 0.7 nm of the catalyst. Potentiodynamic studies of the underpotential deposition of hydrogen (H-upd) on Pt/C electrode in 0.5 mol dm(-3) HClO4 aqueous solution in the temperature range from 274 to 318 K are made, and thermodynamic state functions for the hydrogen adsorption are determined. The experimental results are analyzed assuming linear variation of the Gibbs energy of adsorption versus theta H-upd on the basis of the surface heterogeneity. The increase of Delta G(Hupd)(theta) with the surface coverage indicates the repulsive interactions between H-upd adatoms. From the temperature dependence of the Gibbs energy of adsorption, the enthalpy and the entropy of adsorption are calculated. The values of these functions are determined to be Delta H-Hupd(theta=0) = -5.6 kJ mol(-1) and Delta S-Hupd(theta=0) = 69.1 J mol(-1) K-1 The value of Delta H-Hupd(theta) allows determinations of the bond energy between electrode surface and H-upd that is found to be Ept-H = 223 kJ mol(-1) for theta = 0.",
publisher = "Pergamon-Elsevier Science Ltd, Oxford",
journal = "International Journal of Hydrogen Energy",
title = "Specificity of the UPD of H to the structure of highly dispersed Pt on carbon support",
pages = "1998-1991",
number = "12",
volume = "32",
doi = "10.1016/j.ijhydene.2006.09.042",
url = "https://hdl.handle.net/21.15107/rcub_dais_12884"
}

Elezović, N., Babić, B. M., Krstajić, N., Gajić Krstajić, L.,& Vračar, L.. (2007). Specificity of the UPD of H to the structure of highly dispersed Pt on carbon support. in International Journal of Hydrogen Energy
Pergamon-Elsevier Science Ltd, Oxford., 32(12), 1991-1998.
https://doi.org/10.1016/j.ijhydene.2006.09.042
https://hdl.handle.net/21.15107/rcub_dais_12884

Elezović N, Babić BM, Krstajić N, Gajić Krstajić L, Vračar L. Specificity of the UPD of H to the structure of highly dispersed Pt on carbon support. in International Journal of Hydrogen Energy. 2007;32(12):1991-1998.
doi:10.1016/j.ijhydene.2006.09.042
https://hdl.handle.net/21.15107/rcub_dais_12884 .

Elezović, Nevenka, Babić, Biljana M., Krstajić, Nedeljko, Gajić Krstajić, Ljiljana, Vračar, Ljiljana, "Specificity of the UPD of H to the structure of highly dispersed Pt on carbon support" in International Journal of Hydrogen Energy, 32, no. 12 (2007):1991-1998,
https://doi.org/10.1016/j.ijhydene.2006.09.042 .,
https://hdl.handle.net/21.15107/rcub_dais_12884 .

TY  - JOUR
AU  - Vračar, Ljiljana M.
AU  - Gojković, Snežana Lj.
AU  - Elezović, Nevenka R.
AU  - Radmilović, Velimir R.
AU  - Jaksić, M. M.
AU  - Krstajić, Nedeljko V.
PY  - 2006
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/871
AB  - The impregnation method has been applied to synthesize platinum nanoparticles on Magneli phase titanium oxide powder (Ebonex). Surface area of the Ebonex support was determined by BET technique. Distribution and morphology of Pt nanoparticles in Ebonex/Pt catalyst were analyzed by TEM and HRTEM technique. Rather uniformly dispersed, Pt particles Of 5 +/- 3 nm were observed. The catalyst was tested for oxygen reduction and methanol oxidation in alkaline solution. It was found that in whole potential range oxygen was reduced with four electron exchanged and that the transfer of the first electron was the rate determining step. The kinetics of oxygen reduction on Ebonex/Pt can be described by the same equations as on polycrystalline Pt. When the activities were expressed through the specific current densities, no enhancement for Ebonex/Pt was observed comparing with polycrystalline Pt. Kinetic parameters and specific activity of the methanol oxidation on Ebonex/Pt,was found to be similar to those on polycrystalline Pt as well as to literature data for Pt nanoparticles on other supporting,materials. The Results: for, both reactions investigated indicate that Ebonex does not increase the activity of Pt significantly, bat can serve as a suitable supporting material for nanoparticles in fuel cell catalysts.
T2  - Journal of New Materials for Electrochemical Systems
T1  - Magneli phase titanium oxides as catalyst support - Electrochemical behavior of Ebonex/Pt catalysts
EP  - 106
IS  - 2
SP  - 99
VL  - 9
UR  - https://hdl.handle.net/21.15107/rcub_technorep_871
ER  - 

@article{
author = "Vračar, Ljiljana M. and Gojković, Snežana Lj. and Elezović, Nevenka R. and Radmilović, Velimir R. and Jaksić, M. M. and Krstajić, Nedeljko V.",
year = "2006",
abstract = "The impregnation method has been applied to synthesize platinum nanoparticles on Magneli phase titanium oxide powder (Ebonex). Surface area of the Ebonex support was determined by BET technique. Distribution and morphology of Pt nanoparticles in Ebonex/Pt catalyst were analyzed by TEM and HRTEM technique. Rather uniformly dispersed, Pt particles Of 5 +/- 3 nm were observed. The catalyst was tested for oxygen reduction and methanol oxidation in alkaline solution. It was found that in whole potential range oxygen was reduced with four electron exchanged and that the transfer of the first electron was the rate determining step. The kinetics of oxygen reduction on Ebonex/Pt can be described by the same equations as on polycrystalline Pt. When the activities were expressed through the specific current densities, no enhancement for Ebonex/Pt was observed comparing with polycrystalline Pt. Kinetic parameters and specific activity of the methanol oxidation on Ebonex/Pt,was found to be similar to those on polycrystalline Pt as well as to literature data for Pt nanoparticles on other supporting,materials. The Results: for, both reactions investigated indicate that Ebonex does not increase the activity of Pt significantly, bat can serve as a suitable supporting material for nanoparticles in fuel cell catalysts.",
journal = "Journal of New Materials for Electrochemical Systems",
title = "Magneli phase titanium oxides as catalyst support - Electrochemical behavior of Ebonex/Pt catalysts",
pages = "106-99",
number = "2",
volume = "9",
url = "https://hdl.handle.net/21.15107/rcub_technorep_871"
}

Vračar, L. M., Gojković, S. Lj., Elezović, N. R., Radmilović, V. R., Jaksić, M. M.,& Krstajić, N. V.. (2006). Magneli phase titanium oxides as catalyst support - Electrochemical behavior of Ebonex/Pt catalysts. in Journal of New Materials for Electrochemical Systems, 9(2), 99-106.
https://hdl.handle.net/21.15107/rcub_technorep_871

Vračar LM, Gojković SL, Elezović NR, Radmilović VR, Jaksić MM, Krstajić NV. Magneli phase titanium oxides as catalyst support - Electrochemical behavior of Ebonex/Pt catalysts. in Journal of New Materials for Electrochemical Systems. 2006;9(2):99-106.
https://hdl.handle.net/21.15107/rcub_technorep_871 .

Vračar, Ljiljana M., Gojković, Snežana Lj., Elezović, Nevenka R., Radmilović, Velimir R., Jaksić, M. M., Krstajić, Nedeljko V., "Magneli phase titanium oxides as catalyst support - Electrochemical behavior of Ebonex/Pt catalysts" in Journal of New Materials for Electrochemical Systems, 9, no. 2 (2006):99-106,
https://hdl.handle.net/21.15107/rcub_technorep_871 .

TY  - JOUR
AU  - Obradović, Maja
AU  - Grgur, Branimir
AU  - Gojković, Snežana Lj.
AU  - Vračar, Ljiljana M.
PY  - 2006
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/978
AB  - Polycrystalline Pt electrode was modified by underpotential deposition (upd) of nickel. The modification was performed by potential cycling in phosphate buffer pH 7. 0 containing NiSO4, in which hydrogen and nickel upd processes were well separated. The maximum Ni upd coverage was found to be 0.3. Oxygen reduction was studied at bare and nickel upd-modified Pt. It was found that the reaction rate increased with increasing Ni upd coverage. At theta(Ni)=0.3, the current density was a factor of 2 higher compared to bare Pt (at the potential of 0.85 V). The capacitance of the electrode interface was determined in potential-relaxation experiments following interruption of the polarization current. It was found that the pseudocapacitance owing to a coverage by the adsorbed reaction intermediates was higher on the Ni-modified Pt surface than on bare Pt, which resulted in higher reaction rate. The influence of Ni adatoms on the surface coverage by the reaction intermediates was attributed to the inhibition of OH adsorption on Pt by OH ligands attached on neighboring Ni atoms.
PB  - Springer, New York
T2  - Journal of Solid State Electrochemistry
T1  - Enhancement of the electrochemical reduction of oxygen at platinum by nickel underpotential deposition
EP  - 83
IS  - 1
SP  - 77
VL  - 11
DO  - 10.1007/s10008-005-0072-0
ER  - 

@article{
author = "Obradović, Maja and Grgur, Branimir and Gojković, Snežana Lj. and Vračar, Ljiljana M.",
year = "2006",
abstract = "Polycrystalline Pt electrode was modified by underpotential deposition (upd) of nickel. The modification was performed by potential cycling in phosphate buffer pH 7. 0 containing NiSO4, in which hydrogen and nickel upd processes were well separated. The maximum Ni upd coverage was found to be 0.3. Oxygen reduction was studied at bare and nickel upd-modified Pt. It was found that the reaction rate increased with increasing Ni upd coverage. At theta(Ni)=0.3, the current density was a factor of 2 higher compared to bare Pt (at the potential of 0.85 V). The capacitance of the electrode interface was determined in potential-relaxation experiments following interruption of the polarization current. It was found that the pseudocapacitance owing to a coverage by the adsorbed reaction intermediates was higher on the Ni-modified Pt surface than on bare Pt, which resulted in higher reaction rate. The influence of Ni adatoms on the surface coverage by the reaction intermediates was attributed to the inhibition of OH adsorption on Pt by OH ligands attached on neighboring Ni atoms.",
publisher = "Springer, New York",
journal = "Journal of Solid State Electrochemistry",
title = "Enhancement of the electrochemical reduction of oxygen at platinum by nickel underpotential deposition",
pages = "83-77",
number = "1",
volume = "11",
doi = "10.1007/s10008-005-0072-0"
}

Obradović, M., Grgur, B., Gojković, S. Lj.,& Vračar, L. M.. (2006). Enhancement of the electrochemical reduction of oxygen at platinum by nickel underpotential deposition. in Journal of Solid State Electrochemistry
Springer, New York., 11(1), 77-83.
https://doi.org/10.1007/s10008-005-0072-0

Obradović M, Grgur B, Gojković SL, Vračar LM. Enhancement of the electrochemical reduction of oxygen at platinum by nickel underpotential deposition. in Journal of Solid State Electrochemistry. 2006;11(1):77-83.
doi:10.1007/s10008-005-0072-0 .

Obradović, Maja, Grgur, Branimir, Gojković, Snežana Lj., Vračar, Ljiljana M., "Enhancement of the electrochemical reduction of oxygen at platinum by nickel underpotential deposition" in Journal of Solid State Electrochemistry, 11, no. 1 (2006):77-83,
https://doi.org/10.1007/s10008-005-0072-0 . .

TY  - JOUR
AU  - Dešić, Maja N.
AU  - Popović, Milica M.
AU  - Obradović, Maja
AU  - Vračar, Ljiljana M.
AU  - Grgur, Branimir
PY  - 2005
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/775
AB  - Surface modification of the electrodes was conducted from sulfuric acid solutions containing the corresponding metal-chloride complexes using cyclic voltammeter. Comparing the charges of the hydrogen underpotential deposition region, and the corresponding oxide reduction regions, it is concluded that a platinum overlayer on gold forms 3D islands, while gold on platinum forms 2D islands. Foreign metals present in an amount of up to one monolayer exert an influence on the change in reaction rate with respect to both hydrogen evolution (HER) and oxygen reduction (ORR) reactions. Aplatinum overlayer on a gold substrate increases the activity for HER and for ORR, compared with pure gold. These results can be understood in terms of a simple model, in which the change in the H and OH binding energies are directly proportional to the shift of the d-bond center of the overlayer. On the contrary, a gold layer on platinum slightly decreases the activity for both reactions compared with pure platinum.
AB  - Površinska modifikacija platine zlatom i zlata platinom je izvršena iz rastvora sumporne kiseline i odgovarajućih hloridnih kompleksa metala primenom ciklične voltametrije. Poređenjem količine naelektrisanja u oblasti potpotencijalne depozicije vodonika i odgovarajućih oblasti redukcije oskida čistih i modifikovanih elektroda zaključeno je da platina na zlatu formira 3D, a zlato na platini 2D ostrva. Aktivnosti ovako modifikovanih površina za reakcije izdvajanja vodonika i redukcije kiseonika u rastvoru sumporne kiseline poređene sa aktivnostima čistih metala. Elektroda od zlata modifikovana platinom značajno uvećava aktivnost za obe ispitivane rekacije u poređenju sa čistim zlatom. Sa druge strane, elektroda od platine modifikovana zlatom ima neznatno manju aktivnost u poređenju sa čistom platinom. Zbog ograničenih resursa i visoke cene platine platina modifikovana zlatom može biti zamena za čistu platinu kao dobar katalizator za reakciju redukcije kiseonika, posebno u gorivim spregovima u oblasti niskih temperatura.
PB  - Serbian Chemical Society, Belgrade
T2  - Journal of the Serbian Chemical Society
T1  - Study of gold-platinum and platinum-gold surface modification and its influence on hydrogen evolution and oxygen reduction
T1  - Površinska modifikacija platine zlatom i zlata platinom i njen uticaj na reakcije izdvajanja vodonika i redukcije kiseonika
EP  - 242
IS  - 2
SP  - 231
VL  - 70
UR  - https://hdl.handle.net/21.15107/rcub_technorep_775
ER  - 

@article{
author = "Dešić, Maja N. and Popović, Milica M. and Obradović, Maja and Vračar, Ljiljana M. and Grgur, Branimir",
year = "2005",
abstract = "Surface modification of the electrodes was conducted from sulfuric acid solutions containing the corresponding metal-chloride complexes using cyclic voltammeter. Comparing the charges of the hydrogen underpotential deposition region, and the corresponding oxide reduction regions, it is concluded that a platinum overlayer on gold forms 3D islands, while gold on platinum forms 2D islands. Foreign metals present in an amount of up to one monolayer exert an influence on the change in reaction rate with respect to both hydrogen evolution (HER) and oxygen reduction (ORR) reactions. Aplatinum overlayer on a gold substrate increases the activity for HER and for ORR, compared with pure gold. These results can be understood in terms of a simple model, in which the change in the H and OH binding energies are directly proportional to the shift of the d-bond center of the overlayer. On the contrary, a gold layer on platinum slightly decreases the activity for both reactions compared with pure platinum., Površinska modifikacija platine zlatom i zlata platinom je izvršena iz rastvora sumporne kiseline i odgovarajućih hloridnih kompleksa metala primenom ciklične voltametrije. Poređenjem količine naelektrisanja u oblasti potpotencijalne depozicije vodonika i odgovarajućih oblasti redukcije oskida čistih i modifikovanih elektroda zaključeno je da platina na zlatu formira 3D, a zlato na platini 2D ostrva. Aktivnosti ovako modifikovanih površina za reakcije izdvajanja vodonika i redukcije kiseonika u rastvoru sumporne kiseline poređene sa aktivnostima čistih metala. Elektroda od zlata modifikovana platinom značajno uvećava aktivnost za obe ispitivane rekacije u poređenju sa čistim zlatom. Sa druge strane, elektroda od platine modifikovana zlatom ima neznatno manju aktivnost u poređenju sa čistom platinom. Zbog ograničenih resursa i visoke cene platine platina modifikovana zlatom može biti zamena za čistu platinu kao dobar katalizator za reakciju redukcije kiseonika, posebno u gorivim spregovima u oblasti niskih temperatura.",
publisher = "Serbian Chemical Society, Belgrade",
journal = "Journal of the Serbian Chemical Society",
title = "Study of gold-platinum and platinum-gold surface modification and its influence on hydrogen evolution and oxygen reduction, Površinska modifikacija platine zlatom i zlata platinom i njen uticaj na reakcije izdvajanja vodonika i redukcije kiseonika",
pages = "242-231",
number = "2",
volume = "70",
url = "https://hdl.handle.net/21.15107/rcub_technorep_775"
}

Dešić, M. N., Popović, M. M., Obradović, M., Vračar, L. M.,& Grgur, B.. (2005). Study of gold-platinum and platinum-gold surface modification and its influence on hydrogen evolution and oxygen reduction. in Journal of the Serbian Chemical Society
Serbian Chemical Society, Belgrade., 70(2), 231-242.
https://hdl.handle.net/21.15107/rcub_technorep_775

Dešić MN, Popović MM, Obradović M, Vračar LM, Grgur B. Study of gold-platinum and platinum-gold surface modification and its influence on hydrogen evolution and oxygen reduction. in Journal of the Serbian Chemical Society. 2005;70(2):231-242.
https://hdl.handle.net/21.15107/rcub_technorep_775 .

Dešić, Maja N., Popović, Milica M., Obradović, Maja, Vračar, Ljiljana M., Grgur, Branimir, "Study of gold-platinum and platinum-gold surface modification and its influence on hydrogen evolution and oxygen reduction" in Journal of the Serbian Chemical Society, 70, no. 2 (2005):231-242,
https://hdl.handle.net/21.15107/rcub_technorep_775 .

TY  - JOUR
AU  - Obradović, Maja
AU  - Grgur, Branimir
AU  - Vračar, Ljiljana M.
PY  - 2005
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/716
AB  - Underpotential deposition of nickel and hydrogen on polycrystalline platinum in weak acid and neutral solutions (3.5  lt = pH  lt = 7.0), with and without Ni2+-ions, has been examined using cyclic voltammetric technique in the range of temperature from 274 to 313 K. The nickel and hydrogen ad-atom surface coverages were calculated from the voltammetric adsorption and desorption charges. The Temkin isotherm was fitted for both underpotential depositions, and thermodynamic adsorption parameters were calculated for both atoms. The value of the bonding energy between hydrogen and surface in the presence of underpotentially deposited nickel was calculated and found to amount to 287 kJ mol(-1), which is 40 kJ mol(-1) stronger bond than the same of pure platinum. The presence of nickel on the surface facilitates interfacial transfer of hydrogen into the metal bulk and consequent hydride formation significant in design of hydrogen based fuel cells.
PB  - 6th Conference of the Yugoslav Materials Research Society, YUCOMAT VI: Current Research in Advanced Materials and Processes
T2  - Materials Science Forum
T1  - Comparative potentiodynamic study of nickel and hydrogen underpotential deposition at polycrystalline platinum electrode in weak acid and neutral solutions
EP  - 246
SP  - 241
VL  - 494
DO  - 10.4028/0-87849-971-7.241
ER  - 

@article{
author = "Obradović, Maja and Grgur, Branimir and Vračar, Ljiljana M.",
year = "2005",
abstract = "Underpotential deposition of nickel and hydrogen on polycrystalline platinum in weak acid and neutral solutions (3.5  lt = pH  lt = 7.0), with and without Ni2+-ions, has been examined using cyclic voltammetric technique in the range of temperature from 274 to 313 K. The nickel and hydrogen ad-atom surface coverages were calculated from the voltammetric adsorption and desorption charges. The Temkin isotherm was fitted for both underpotential depositions, and thermodynamic adsorption parameters were calculated for both atoms. The value of the bonding energy between hydrogen and surface in the presence of underpotentially deposited nickel was calculated and found to amount to 287 kJ mol(-1), which is 40 kJ mol(-1) stronger bond than the same of pure platinum. The presence of nickel on the surface facilitates interfacial transfer of hydrogen into the metal bulk and consequent hydride formation significant in design of hydrogen based fuel cells.",
publisher = "6th Conference of the Yugoslav Materials Research Society, YUCOMAT VI: Current Research in Advanced Materials and Processes",
journal = "Materials Science Forum",
title = "Comparative potentiodynamic study of nickel and hydrogen underpotential deposition at polycrystalline platinum electrode in weak acid and neutral solutions",
pages = "246-241",
volume = "494",
doi = "10.4028/0-87849-971-7.241"
}

Obradović, M., Grgur, B.,& Vračar, L. M.. (2005). Comparative potentiodynamic study of nickel and hydrogen underpotential deposition at polycrystalline platinum electrode in weak acid and neutral solutions. in Materials Science Forum
6th Conference of the Yugoslav Materials Research Society, YUCOMAT VI: Current Research in Advanced Materials and Processes., 494, 241-246.
https://doi.org/10.4028/0-87849-971-7.241

Obradović M, Grgur B, Vračar LM. Comparative potentiodynamic study of nickel and hydrogen underpotential deposition at polycrystalline platinum electrode in weak acid and neutral solutions. in Materials Science Forum. 2005;494:241-246.
doi:10.4028/0-87849-971-7.241 .

Obradović, Maja, Grgur, Branimir, Vračar, Ljiljana M., "Comparative potentiodynamic study of nickel and hydrogen underpotential deposition at polycrystalline platinum electrode in weak acid and neutral solutions" in Materials Science Forum, 494 (2005):241-246,
https://doi.org/10.4028/0-87849-971-7.241 . .

TY  - JOUR
AU  - Obradović, Maja
AU  - Grgur, Branimir
AU  - Vračar, Ljiljana M.
PY  - 2004
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/596
AB  - Oxygen reduction (OR) at a Pt3Co alloy electrode has been examined in alkaline solutions of different pH's in the temperature range from 274 to 313 K. At all temperatures, two distinct E-log j rep-ions are observed. At low current densities (cd), Tafel slopes are close to -2.3 RT/F while at high current densities they are close to -2 x 2.3RT/F. The Tafel slopes at all pH values closely follow the kconventional temperature dependence with beta = 1/2. In addition, to confirm the mechanism in the two cd regions, the apparent enthalpies of activation at the selected potentials are calculated in both low and high cd regions at different pH. Although the relation DeltaH(a,J c.d)*  gt  DeltaH(a,h .c.d)(not equal) was found to be valid. it is concluded that at every pH, at the zero Galvani potential difference, the enthalples of activation are identical, and the rate determining step of OR reaction is the same in both cd regions. The changes in the Tafel slopes arise from different adsorption conditions of reaction intermediates in these regions as previously suggested [1].
PB  - Progress in Advanced Materials and Processes: Proceedings of the Fifth Jugoslav Materials Research Society, YUCOMAT V
T2  - Materials Science Forum
T1  - Apparent enthalpies of activation for oxygen reduction at Pt3Co electrode in alkaline solution
EP  - 114
SP  - 109
VL  - 453-454
UR  - https://hdl.handle.net/21.15107/rcub_technorep_596
ER  - 

@article{
author = "Obradović, Maja and Grgur, Branimir and Vračar, Ljiljana M.",
year = "2004",
abstract = "Oxygen reduction (OR) at a Pt3Co alloy electrode has been examined in alkaline solutions of different pH's in the temperature range from 274 to 313 K. At all temperatures, two distinct E-log j rep-ions are observed. At low current densities (cd), Tafel slopes are close to -2.3 RT/F while at high current densities they are close to -2 x 2.3RT/F. The Tafel slopes at all pH values closely follow the kconventional temperature dependence with beta = 1/2. In addition, to confirm the mechanism in the two cd regions, the apparent enthalpies of activation at the selected potentials are calculated in both low and high cd regions at different pH. Although the relation DeltaH(a,J c.d)*  gt  DeltaH(a,h .c.d)(not equal) was found to be valid. it is concluded that at every pH, at the zero Galvani potential difference, the enthalples of activation are identical, and the rate determining step of OR reaction is the same in both cd regions. The changes in the Tafel slopes arise from different adsorption conditions of reaction intermediates in these regions as previously suggested [1].",
publisher = "Progress in Advanced Materials and Processes: Proceedings of the Fifth Jugoslav Materials Research Society, YUCOMAT V",
journal = "Materials Science Forum",
title = "Apparent enthalpies of activation for oxygen reduction at Pt3Co electrode in alkaline solution",
pages = "114-109",
volume = "453-454",
url = "https://hdl.handle.net/21.15107/rcub_technorep_596"
}

Obradović, M., Grgur, B.,& Vračar, L. M.. (2004). Apparent enthalpies of activation for oxygen reduction at Pt3Co electrode in alkaline solution. in Materials Science Forum
Progress in Advanced Materials and Processes: Proceedings of the Fifth Jugoslav Materials Research Society, YUCOMAT V., 453-454, 109-114.
https://hdl.handle.net/21.15107/rcub_technorep_596

Obradović M, Grgur B, Vračar LM. Apparent enthalpies of activation for oxygen reduction at Pt3Co electrode in alkaline solution. in Materials Science Forum. 2004;453-454:109-114.
https://hdl.handle.net/21.15107/rcub_technorep_596 .

Obradović, Maja, Grgur, Branimir, Vračar, Ljiljana M., "Apparent enthalpies of activation for oxygen reduction at Pt3Co electrode in alkaline solution" in Materials Science Forum, 453-454 (2004):109-114,
https://hdl.handle.net/21.15107/rcub_technorep_596 .

TY  - JOUR
AU  - Obradović, Maja
AU  - Grgur, Branimir
AU  - Vračar, Ljiljana M.
PY  - 2003
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/516
AB  - A rotating Pt3Co, thermally prepared alloy disc is used to study electrochemical oxygen reduction in alkaline solutions of different pH. In all solutions two Tafel regions are found: at low current densities partial derivativeE/partial derivativelog j = -2.3RT/F and at high current densities partial derivativeE/log j = -2.3 x 2RT/F. The reaction order with respect to OH- is confirmed to be -1/2 and 0 for low and high current density regions, respectively. The coverage, theta, with oxygen intermediates, determined by a programmed potentiodynamic method, is found to be a function of potential and pH. In all solutions, substantial coverages are observed only at potentials in the low current density region. It is found that the fractional reaction order at low current densities is related through the adsorption of oxygen species under Temkin conditions and the dependence of activation energy on theta and pH.
PB  - Elsevier Science Sa, Lausanne
T2  - Journal of Electroanalytical Chemistry
T1  - Adsorption of oxygen containing species and their effect on oxygen reduction on Pt3Co electrode
EP  - 78
SP  - 69
VL  - 548
DO  - 10.1016/S0022-0728(03)00223-7
ER  - 

@article{
author = "Obradović, Maja and Grgur, Branimir and Vračar, Ljiljana M.",
year = "2003",
abstract = "A rotating Pt3Co, thermally prepared alloy disc is used to study electrochemical oxygen reduction in alkaline solutions of different pH. In all solutions two Tafel regions are found: at low current densities partial derivativeE/partial derivativelog j = -2.3RT/F and at high current densities partial derivativeE/log j = -2.3 x 2RT/F. The reaction order with respect to OH- is confirmed to be -1/2 and 0 for low and high current density regions, respectively. The coverage, theta, with oxygen intermediates, determined by a programmed potentiodynamic method, is found to be a function of potential and pH. In all solutions, substantial coverages are observed only at potentials in the low current density region. It is found that the fractional reaction order at low current densities is related through the adsorption of oxygen species under Temkin conditions and the dependence of activation energy on theta and pH.",
publisher = "Elsevier Science Sa, Lausanne",
journal = "Journal of Electroanalytical Chemistry",
title = "Adsorption of oxygen containing species and their effect on oxygen reduction on Pt3Co electrode",
pages = "78-69",
volume = "548",
doi = "10.1016/S0022-0728(03)00223-7"
}

Obradović, M., Grgur, B.,& Vračar, L. M.. (2003). Adsorption of oxygen containing species and their effect on oxygen reduction on Pt3Co electrode. in Journal of Electroanalytical Chemistry
Elsevier Science Sa, Lausanne., 548, 69-78.
https://doi.org/10.1016/S0022-0728(03)00223-7

Obradović M, Grgur B, Vračar LM. Adsorption of oxygen containing species and their effect on oxygen reduction on Pt3Co electrode. in Journal of Electroanalytical Chemistry. 2003;548:69-78.
doi:10.1016/S0022-0728(03)00223-7 .

Obradović, Maja, Grgur, Branimir, Vračar, Ljiljana M., "Adsorption of oxygen containing species and their effect on oxygen reduction on Pt3Co electrode" in Journal of Electroanalytical Chemistry, 548 (2003):69-78,
https://doi.org/10.1016/S0022-0728(03)00223-7 . .

TY  - JOUR
AU  - Vračar, Ljiljana
PY  - 2001
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/5352
AB  - The competitive adsorption of organic molecules (2, 7-naphthalenedisulfonic acid) and adsorbed H is of interest in relation to its influence on H absorption into a Pd-Ni electro-deposited alloy. The experimental results, in acid solution, show an enhancement of the coverage of the electrode surface with adosrbed H due to the competitive adsorption of organic molecules that interfere with H atoms, through lateral attractive interactions between the adsorbed species and communal electronic effects, leading supposedly to a decreased probability of H entry into the alloy. Chemisorbed H is, on the other hand, an intermediate in the HER, so the enhancement of the electrode coverage in the presence of co-adsorbed organic molecules promotes the hydrogen evolution reaction.
PB  - Serbian Chemical Society
T2  - Journal of the Serbian Chemical Society
T1  - The effect of organic molecules adsorption on hydrogen absorption in relation to the hydrogen evolution reaction
EP  - 809
IS  - 11-12
SP  - 799
VL  - 66
DO  - 10.2298/jsc0112799v
ER  - 

@article{
author = "Vračar, Ljiljana",
year = "2001",
abstract = "The competitive adsorption of organic molecules (2, 7-naphthalenedisulfonic acid) and adsorbed H is of interest in relation to its influence on H absorption into a Pd-Ni electro-deposited alloy. The experimental results, in acid solution, show an enhancement of the coverage of the electrode surface with adosrbed H due to the competitive adsorption of organic molecules that interfere with H atoms, through lateral attractive interactions between the adsorbed species and communal electronic effects, leading supposedly to a decreased probability of H entry into the alloy. Chemisorbed H is, on the other hand, an intermediate in the HER, so the enhancement of the electrode coverage in the presence of co-adsorbed organic molecules promotes the hydrogen evolution reaction.",
publisher = "Serbian Chemical Society",
journal = "Journal of the Serbian Chemical Society",
title = "The effect of organic molecules adsorption on hydrogen absorption in relation to the hydrogen evolution reaction",
pages = "809-799",
number = "11-12",
volume = "66",
doi = "10.2298/jsc0112799v"
}

Vračar, L.. (2001). The effect of organic molecules adsorption on hydrogen absorption in relation to the hydrogen evolution reaction. in Journal of the Serbian Chemical Society
Serbian Chemical Society., 66(11-12), 799-809.
https://doi.org/10.2298/jsc0112799v

Vračar L. The effect of organic molecules adsorption on hydrogen absorption in relation to the hydrogen evolution reaction. in Journal of the Serbian Chemical Society. 2001;66(11-12):799-809.
doi:10.2298/jsc0112799v .

Vračar, Ljiljana, "The effect of organic molecules adsorption on hydrogen absorption in relation to the hydrogen evolution reaction" in Journal of the Serbian Chemical Society, 66, no. 11-12 (2001):799-809,
https://doi.org/10.2298/jsc0112799v . .