E. Herrero et al., CO ADSORPTION AND OXIDATION ON PT(111) ELECTRODES MODIFIED BY IRREVERSIBLY ADSORBED BISMUTH IN SULFURIC-ACID MEDIUM, Journal of catalysis, 152(2), 1995, pp. 264-274
CO adsorption and desorption (''stripping'') on Pt(111) electrodes mod
ified by irreversibly adsorbed bismuth have been studied. The presence
of CO adsorbed on the Bi-Pt(111) electrode modifies the redox peak of
the adsorbed bismuth, suggesting the presence of a CO-Bi mixed adlaye
r. Using the CO stripping charge after appropriate correction, the val
ues of CO coverage for the different bismuth coverages were calculated
, as well as the proportions of linear and bridged-bonded CO. Unlike i
n UHV environments, the presence of bismuth on the surface favors the
linear configuration of the adsorbed CO. At Theta(Bi) = 0.15, the CO p
opulation is almost entirely constituted linear CO, regardless of the
CO coverage. Transient CO stripping demonstrates that the presence of
bismuth on the surface enhances CO oxidation through bismuth-mediated
oxygen transfer. (C) 1995 Academic Press, Inc.