Electrochemical and Surface-enhanced Raman Studies of CO and Methanol Oxidation in the Presence of Sub-monolayer Co-adsorbed Sulfur

by Mattox, Mathew Allen

Electrooxidation of carbon monoxide (CO) and methanol on platinum are two important reactions in direct methanol fuel cells. The presence of coadsorbates often modifies the reaction significantly. In this thesis we report our studies on the effects of adsorbed sulfur on CO and methanol electrooxidation on Pt. Although adsorbed sulfur is often considered a surface poison, the cyclic voltammetric and chronoamperometric results show that the presence of a sub-monolayer of adsorbed sulfur promotes the aforementioned reactions. Surface-enhanced Raman spectroscopy, together with electrochemical results, was used to elucidate a possible mechanism of the enhancement effect.