Kinetic and mechanistic study of methanol oxidation on a Pt(110) surface in alkaline media

The comparative study of methanol oxidation on a Pt(110) surface was carried out in bicarbonate, carbonate and sodium hydroxide solutions. It was shown that OH− electrosorption precedes the oxide layer formation in sodium hydroxide solution and is coupled by HCO3− and CO32− electrosorption in the corresponding media. Adsorbed bicarbonates suppressed the methanol oxidation. The surface activity was correlated to the OHad species coverage. Coverage with `poisoning species' formed during methanol oxidation is time dependent. The dual path mechanism for methanol oxidation on the Pt(110) surface, as well as for the other low-index planes, was proposed based on the assumptions that HCOad and OHad are reactive intermediates and that formate is the reaction product in the main path, while CO2 is a product of `poisoning species' oxidation in a parallel reaction path.