TY  - JOUR
AU  - Schmidt, TJ
AU  - Behm, RJ
AU  - Grgur, Branimir
AU  - Marković, NM
AU  - Ross, PN
PY  - 2000
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/304
AB  - Temperature effects on the kinetics of formic acid electrooxidation are studied on Pt(111) and on Pt(111) modified by irreversibly adsorbed Bi under both potentiodynamic and potentiostatic conditions. We propose two modes of action of irreversibly adsorbed Pi on the kinetics of HCOOH oxidation: (i) the inhibiting effect due to a blocking of active Pt sites and (ii) the catalytic effect due to the enhanced adsorption of OHad on the Pt sites adjacent to Bi. This counteracting behavior led to the fact that under steady-state conditions no difference in the overall activity was observed between Pt(111) and Pt(111)/Bi. Therefore, Pt(111)/Bi does not represent a catalytically active system of technological relevance.
PB  - Amer Chemical Soc, Washington
T2  - Langmuir
T1  - Formic acid oxidation on pure and Bi-modified Pt(111): Temperature effects
EP  - 8166
IS  - 21
SP  - 8159
VL  - 16
DO  - 10.1021/la000339z
ER  - 

@article{
author = "Schmidt, TJ and Behm, RJ and Grgur, Branimir and Marković, NM and Ross, PN",
year = "2000",
abstract = "Temperature effects on the kinetics of formic acid electrooxidation are studied on Pt(111) and on Pt(111) modified by irreversibly adsorbed Bi under both potentiodynamic and potentiostatic conditions. We propose two modes of action of irreversibly adsorbed Pi on the kinetics of HCOOH oxidation: (i) the inhibiting effect due to a blocking of active Pt sites and (ii) the catalytic effect due to the enhanced adsorption of OHad on the Pt sites adjacent to Bi. This counteracting behavior led to the fact that under steady-state conditions no difference in the overall activity was observed between Pt(111) and Pt(111)/Bi. Therefore, Pt(111)/Bi does not represent a catalytically active system of technological relevance.",
publisher = "Amer Chemical Soc, Washington",
journal = "Langmuir",
title = "Formic acid oxidation on pure and Bi-modified Pt(111): Temperature effects",
pages = "8166-8159",
number = "21",
volume = "16",
doi = "10.1021/la000339z"
}

Schmidt, T., Behm, R., Grgur, B., Marković, N.,& Ross, P.. (2000). Formic acid oxidation on pure and Bi-modified Pt(111): Temperature effects. in Langmuir
Amer Chemical Soc, Washington., 16(21), 8159-8166.
https://doi.org/10.1021/la000339z

Schmidt T, Behm R, Grgur B, Marković N, Ross P. Formic acid oxidation on pure and Bi-modified Pt(111): Temperature effects. in Langmuir. 2000;16(21):8159-8166.
doi:10.1021/la000339z .

Schmidt, TJ, Behm, RJ, Grgur, Branimir, Marković, NM, Ross, PN, "Formic acid oxidation on pure and Bi-modified Pt(111): Temperature effects" in Langmuir, 16, no. 21 (2000):8159-8166,
https://doi.org/10.1021/la000339z . .

TY  - JOUR
AU  - Schmidt, TJ
AU  - Grgur, Branimir
AU  - Behm, RJ
AU  - Marković, NM
AU  - Ross, PN
PY  - 2000
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/303
AB  - The surface electrochemistry of reversibly and irreversibly adsorbed bismuth (Bi-ad) was studied on Pt(111) electrodes in 0.1 M HClO4. The valence state of irreversibly adsorbed Bi (Bi-ir) was determined by ex situ X-ray photoelectron spectroscopy (XPS). It was shown that Bi-ir does not change its valence state during potential cycling and is adsorbed in its metallic (i.e., zero-valent) state. Underpotential deposition (UPD) of Bi (Bi-upd) onto Pt(111) was studied using the rotating ring-disk electrode (RRDE) technique for measurements of the Bi3+ ion specific flux. The total amount of Bi deposited at underpotential (Theta(Bi,upd)) was determined by integration of the ion specific flux, and found to be approximate to 0.16 ML (1 ML=1 Bi/1 Pt). The UPD Bi is assumed to deposit at bare Pt sites not occupied by the irreversibly adsorbed Bi. The difference between Theta(Bi,upd) and the maximum coverage of a close-packed monolayer of fully discharged Bi adatoms (Theta(Biad)=0.56 ML) is taken to equal the coverage by Bi-ir, or approximate to 1/3 ML. The charge under the reversible peak in the Pt(111)/Bi-ir voltammetry (Q=160 mu C cm(-2)) for Theta(Bi,ir)similar to 1/3 ML is ascribed to enhanced adsorption of OH on Pt sites adjacent to Bi due to a change of the local potential of zero charge (p.z.c.) induced by Bi. Contrasting kinetic effects of Bi-ir were observed on the hydrogen and carbon monoxide oxidation reactions. These effects are discussed in terms of the known role of OHad in these reactions on the Pt(111) surface.
PB  - Royal Soc Chemistry, Cambridge
T2  - Physical Chemistry Chemical Physics
T1  - Bi adsorption on Pt(111) in perchloric acid solution: A rotating ring-disk electrode and XPS study
EP  - 4386
IS  - 19
SP  - 4379
VL  - 2
DO  - 10.1039/b003767m
ER  - 

@article{
author = "Schmidt, TJ and Grgur, Branimir and Behm, RJ and Marković, NM and Ross, PN",
year = "2000",
abstract = "The surface electrochemistry of reversibly and irreversibly adsorbed bismuth (Bi-ad) was studied on Pt(111) electrodes in 0.1 M HClO4. The valence state of irreversibly adsorbed Bi (Bi-ir) was determined by ex situ X-ray photoelectron spectroscopy (XPS). It was shown that Bi-ir does not change its valence state during potential cycling and is adsorbed in its metallic (i.e., zero-valent) state. Underpotential deposition (UPD) of Bi (Bi-upd) onto Pt(111) was studied using the rotating ring-disk electrode (RRDE) technique for measurements of the Bi3+ ion specific flux. The total amount of Bi deposited at underpotential (Theta(Bi,upd)) was determined by integration of the ion specific flux, and found to be approximate to 0.16 ML (1 ML=1 Bi/1 Pt). The UPD Bi is assumed to deposit at bare Pt sites not occupied by the irreversibly adsorbed Bi. The difference between Theta(Bi,upd) and the maximum coverage of a close-packed monolayer of fully discharged Bi adatoms (Theta(Biad)=0.56 ML) is taken to equal the coverage by Bi-ir, or approximate to 1/3 ML. The charge under the reversible peak in the Pt(111)/Bi-ir voltammetry (Q=160 mu C cm(-2)) for Theta(Bi,ir)similar to 1/3 ML is ascribed to enhanced adsorption of OH on Pt sites adjacent to Bi due to a change of the local potential of zero charge (p.z.c.) induced by Bi. Contrasting kinetic effects of Bi-ir were observed on the hydrogen and carbon monoxide oxidation reactions. These effects are discussed in terms of the known role of OHad in these reactions on the Pt(111) surface.",
publisher = "Royal Soc Chemistry, Cambridge",
journal = "Physical Chemistry Chemical Physics",
title = "Bi adsorption on Pt(111) in perchloric acid solution: A rotating ring-disk electrode and XPS study",
pages = "4386-4379",
number = "19",
volume = "2",
doi = "10.1039/b003767m"
}

Schmidt, T., Grgur, B., Behm, R., Marković, N.,& Ross, P.. (2000). Bi adsorption on Pt(111) in perchloric acid solution: A rotating ring-disk electrode and XPS study. in Physical Chemistry Chemical Physics
Royal Soc Chemistry, Cambridge., 2(19), 4379-4386.
https://doi.org/10.1039/b003767m

Schmidt T, Grgur B, Behm R, Marković N, Ross P. Bi adsorption on Pt(111) in perchloric acid solution: A rotating ring-disk electrode and XPS study. in Physical Chemistry Chemical Physics. 2000;2(19):4379-4386.
doi:10.1039/b003767m .

Schmidt, TJ, Grgur, Branimir, Behm, RJ, Marković, NM, Ross, PN, "Bi adsorption on Pt(111) in perchloric acid solution: A rotating ring-disk electrode and XPS study" in Physical Chemistry Chemical Physics, 2, no. 19 (2000):4379-4386,
https://doi.org/10.1039/b003767m . .

TY  - JOUR
AU  - Marković, NM
AU  - Schmidt, TJ
AU  - Grgur, Branimir
AU  - Gasteiger, HA
AU  - Behm, RJ
AU  - Ross, PN
PY  - 1999
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/266
AB  - The variation of the adsorption pseudocapacitance with temperature is used to obtain the enthalpy, entropy, and free energies of adsorption of H-upd and OHad on Pt(lll) as a function of pH and nature of the anion of the supporting electrolyte. It is shown that the heat (enthalpy) of adsorption of hydrogen on Pt(lll) at the electrochemical interface is essentially independent of either the pH of the electrolyte or the nature of the supporting anion. The heat of adsorption has a linear decrease with Theta(Hupd,) from similar to 42 kJ/mol at Theta(Hupd) = 0 ML to similar to 24 kJ/mol at Theta(Hupd) = 0.66 ML. The heat of adsorption of OHad is more sensitive to the nature of the anion in the supporting electrolyte. This is presumably due to coadsorption of the anion and OHad in electrolytes other than the simple alkali bases. From the isosteric heat of adsorption of OHad in alkaline solution (ca. similar to 200 kJ/mol) and the enthalpy of formation of OH. we estimated the Pt(111)-OHad bond energy of 136 kJ/mol. This value is much. smaller than the Pt-O-ad bond energy at a gas-solid interface (similar to 350 kJ/mol). In basic solution the electrooxidation of CO proceeds at low overpotentials ( lt 0.2 V) between the adsorbed states of COad and OHad, the latter forming at low overpotentials selectively at defect sites. In acid solution, however; these sites are not active because they are blocked by specific adsorption of anions of the supporting electrolyte.
PB  - Amer Chemical Soc, Washington
T2  - Journal of Physical Chemistry B
T1  - Effect of temperature on surface processes at the Pt(111)-liquid interface: Hydrogen adsorption, oxide formation, and CO oxidation
EP  - 8577
IS  - 40
SP  - 8568
VL  - 103
DO  - 10.1021/jp991826u
ER  - 

@article{
author = "Marković, NM and Schmidt, TJ and Grgur, Branimir and Gasteiger, HA and Behm, RJ and Ross, PN",
year = "1999",
abstract = "The variation of the adsorption pseudocapacitance with temperature is used to obtain the enthalpy, entropy, and free energies of adsorption of H-upd and OHad on Pt(lll) as a function of pH and nature of the anion of the supporting electrolyte. It is shown that the heat (enthalpy) of adsorption of hydrogen on Pt(lll) at the electrochemical interface is essentially independent of either the pH of the electrolyte or the nature of the supporting anion. The heat of adsorption has a linear decrease with Theta(Hupd,) from similar to 42 kJ/mol at Theta(Hupd) = 0 ML to similar to 24 kJ/mol at Theta(Hupd) = 0.66 ML. The heat of adsorption of OHad is more sensitive to the nature of the anion in the supporting electrolyte. This is presumably due to coadsorption of the anion and OHad in electrolytes other than the simple alkali bases. From the isosteric heat of adsorption of OHad in alkaline solution (ca. similar to 200 kJ/mol) and the enthalpy of formation of OH. we estimated the Pt(111)-OHad bond energy of 136 kJ/mol. This value is much. smaller than the Pt-O-ad bond energy at a gas-solid interface (similar to 350 kJ/mol). In basic solution the electrooxidation of CO proceeds at low overpotentials ( lt 0.2 V) between the adsorbed states of COad and OHad, the latter forming at low overpotentials selectively at defect sites. In acid solution, however; these sites are not active because they are blocked by specific adsorption of anions of the supporting electrolyte.",
publisher = "Amer Chemical Soc, Washington",
journal = "Journal of Physical Chemistry B",
title = "Effect of temperature on surface processes at the Pt(111)-liquid interface: Hydrogen adsorption, oxide formation, and CO oxidation",
pages = "8577-8568",
number = "40",
volume = "103",
doi = "10.1021/jp991826u"
}

Marković, N., Schmidt, T., Grgur, B., Gasteiger, H., Behm, R.,& Ross, P.. (1999). Effect of temperature on surface processes at the Pt(111)-liquid interface: Hydrogen adsorption, oxide formation, and CO oxidation. in Journal of Physical Chemistry B
Amer Chemical Soc, Washington., 103(40), 8568-8577.
https://doi.org/10.1021/jp991826u

Marković N, Schmidt T, Grgur B, Gasteiger H, Behm R, Ross P. Effect of temperature on surface processes at the Pt(111)-liquid interface: Hydrogen adsorption, oxide formation, and CO oxidation. in Journal of Physical Chemistry B. 1999;103(40):8568-8577.
doi:10.1021/jp991826u .

Marković, NM, Schmidt, TJ, Grgur, Branimir, Gasteiger, HA, Behm, RJ, Ross, PN, "Effect of temperature on surface processes at the Pt(111)-liquid interface: Hydrogen adsorption, oxide formation, and CO oxidation" in Journal of Physical Chemistry B, 103, no. 40 (1999):8568-8577,
https://doi.org/10.1021/jp991826u . .