Приказ основних података о документу
Electrooxidation of H-2, CO, and H-2/CO mixtures on a well-characterized Pt70Mo30 bulk alloy electrode
dc.creator | Grgur, Branimir | |
dc.creator | Marković, NM | |
dc.creator | Ross, PN | |
dc.date.accessioned | 2021-03-10T09:44:44Z | |
dc.date.available | 2021-03-10T09:44:44Z | |
dc.date.issued | 1998 | |
dc.identifier.issn | 1089-5647 | |
dc.identifier.uri | http://TechnoRep.tmf.bg.ac.rs/handle/123456789/188 | |
dc.description.abstract | The electrochemical oxidation of hydrogen (H-2), carbon monoxide (CO), and their mixtures (500 ppm-2%) on a well-characterized Pt70Mo30 bulk alloy was examined using the rotating disk electrode technique in 0.5 M H2SO4 at 333 K, The electrodes were transferred to and from a UHV chamber, where surface analyses were conducted using a combination of low-energy ion scattering (LEIS), Auger electron spectroscopy (AES), and X-ray photoelectron spectroscopy (XPS). The surface composition of this alloy after sputter-etching and annealing in UHV was slightly enriched in Pt to a composition of Pt77Mo23 The kinetics of H-2 oxidation are not measurably affected by the presence of the Mo in the surface. The shapes of the polarization curves for the oxidation of the H-2/CO mixtures are qualitatively similar to those for the Pt50Ru50 alloy examined previously: a high current-potential slope ica. 0.5 V/dec at low overpotential followed by a transition to a highly active state when the current approaches the diffusion-limiting current; the potential where the transition to the active state occurs decreases with decreasing CO concentration and decreases with increasing temperature; the current in the low-overpotential region is roughly inverse half-order in the CO partial pressure. The current densities in the low-overpotential region an comparable to those on Pt50Ru50 alloy and about a factor Or 50 times those on a pure rt surface, while the anodic stripping of irreversibly adsorbed CO is very different from that on the Pt50Ru50 alloy, with most of the COads being oxidized only above 0.6 V (RHE), there is direct evidence for the oxidation of small amounts of COads in the low-overpotential region of 0.05-0.5 V. The mechanism of action of Mo in the Pt surface in enhancing Hr oxidation in the presence of CO thus appears to be very similar to that of Ru: a reduction in the steady-state coverage of COads on the Pt sites by oxidative removal, freeing Pt sites for H-2 oxidation. | en |
dc.publisher | Amer Chemical Soc, Washington | |
dc.rights | restrictedAccess | |
dc.source | Journal of Physical Chemistry B | |
dc.title | Electrooxidation of H-2, CO, and H-2/CO mixtures on a well-characterized Pt70Mo30 bulk alloy electrode | en |
dc.type | article | |
dc.rights.license | ARR | |
dc.citation.epage | 2501 | |
dc.citation.issue | 14 | |
dc.citation.other | 102(14): 2494-2501 | |
dc.citation.rank | M21 | |
dc.citation.spage | 2494 | |
dc.citation.volume | 102 | |
dc.identifier.doi | 10.1021/jp972692s | |
dc.identifier.scopus | 2-s2.0-0000614988 | |
dc.identifier.wos | 000073043700008 | |
dc.type.version | publishedVersion |