We report new results for the electrooxidation of Hz, CO and H-2/CO mixtures on a Pt75Re25 bulk alloy using surface preparation in a UHV chamber and characterization by X-ray photoelectron spectroscopy (XPS). Sputter-cleaned but not-annealed surfaces having the bulk composition were used. This alloy surface has unique properties for CO electrooxidation: finite current densities below 0.2 V (rhe), a positive reaction order in CO partial pressure of +0.5, but an unusually high slope in the log i vs E curve, about 220;mV per decade. Anodic stripping of the irreversibly adsorbed CO on this surface also occurs at an unusually low potential, initiating at about 0.15 V, but only about 1/3 of the total amount of CO on the surface is oxidized at 0.15-0.4 V, the remainder being oxidized at 0.6-0.8 V. The polarization curves for the oxidation of H-2/CO mixtures containing 0.1-2% CO are, however, very Pt-like. It appears that the low-potential oxidation of both dissolved CO and adsorbed CO on this... surface occurs exclusively at Re sites, so that with the H-2/CO mixture the Pt sites remain fully covered (and thus deactivated) by COads.
TY - JOUR
AU - Grgur, Branimir
AU - Marković, NM
AU - Ross, PN
PY - 1998
UR - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/218
AB - We report new results for the electrooxidation of Hz, CO and H-2/CO mixtures on a Pt75Re25 bulk alloy using surface preparation in a UHV chamber and characterization by X-ray photoelectron spectroscopy (XPS). Sputter-cleaned but not-annealed surfaces having the bulk composition were used. This alloy surface has unique properties for CO electrooxidation: finite current densities below 0.2 V (rhe), a positive reaction order in CO partial pressure of +0.5, but an unusually high slope in the log i vs E curve, about 220;mV per decade. Anodic stripping of the irreversibly adsorbed CO on this surface also occurs at an unusually low potential, initiating at about 0.15 V, but only about 1/3 of the total amount of CO on the surface is oxidized at 0.15-0.4 V, the remainder being oxidized at 0.6-0.8 V. The polarization curves for the oxidation of H-2/CO mixtures containing 0.1-2% CO are, however, very Pt-like. It appears that the low-potential oxidation of both dissolved CO and adsorbed CO on this surface occurs exclusively at Re sites, so that with the H-2/CO mixture the Pt sites remain fully covered (and thus deactivated) by COads.
PB - Pergamon-Elsevier Science Ltd, Oxford
T2 - Electrochimica Acta
T1 - Electrooxidation of H-2, CO and H-2/CO mixtures on a well-characterized Pt-Re bulk alloy electrode and comparison with other Pt binary alloys
EP - 3635
IS - 24
SP - 3631
VL - 43
DO - 10.1016/S0013-4686(98)00120-0
ER -
@article{
author = "Grgur, Branimir and Marković, NM and Ross, PN",
year = "1998",
abstract = "We report new results for the electrooxidation of Hz, CO and H-2/CO mixtures on a Pt75Re25 bulk alloy using surface preparation in a UHV chamber and characterization by X-ray photoelectron spectroscopy (XPS). Sputter-cleaned but not-annealed surfaces having the bulk composition were used. This alloy surface has unique properties for CO electrooxidation: finite current densities below 0.2 V (rhe), a positive reaction order in CO partial pressure of +0.5, but an unusually high slope in the log i vs E curve, about 220;mV per decade. Anodic stripping of the irreversibly adsorbed CO on this surface also occurs at an unusually low potential, initiating at about 0.15 V, but only about 1/3 of the total amount of CO on the surface is oxidized at 0.15-0.4 V, the remainder being oxidized at 0.6-0.8 V. The polarization curves for the oxidation of H-2/CO mixtures containing 0.1-2% CO are, however, very Pt-like. It appears that the low-potential oxidation of both dissolved CO and adsorbed CO on this surface occurs exclusively at Re sites, so that with the H-2/CO mixture the Pt sites remain fully covered (and thus deactivated) by COads.",
publisher = "Pergamon-Elsevier Science Ltd, Oxford",
journal = "Electrochimica Acta",
title = "Electrooxidation of H-2, CO and H-2/CO mixtures on a well-characterized Pt-Re bulk alloy electrode and comparison with other Pt binary alloys",
pages = "3635-3631",
number = "24",
volume = "43",
doi = "10.1016/S0013-4686(98)00120-0"
}
Grgur, B., Marković, N.,& Ross, P.. (1998). Electrooxidation of H-2, CO and H-2/CO mixtures on a well-characterized Pt-Re bulk alloy electrode and comparison with other Pt binary alloys. in Electrochimica Acta
Pergamon-Elsevier Science Ltd, Oxford., 43(24), 3631-3635.
https://doi.org/10.1016/S0013-4686(98)00120-0
Grgur B, Marković N, Ross P. Electrooxidation of H-2, CO and H-2/CO mixtures on a well-characterized Pt-Re bulk alloy electrode and comparison with other Pt binary alloys. in Electrochimica Acta. 1998;43(24):3631-3635.
doi:10.1016/S0013-4686(98)00120-0 .
Grgur, Branimir, Marković, NM, Ross, PN, "Electrooxidation of H-2, CO and H-2/CO mixtures on a well-characterized Pt-Re bulk alloy electrode and comparison with other Pt binary alloys" in Electrochimica Acta, 43, no. 24 (1998):3631-3635,
https://doi.org/10.1016/S0013-4686(98)00120-0 . .
