Temperature Tuned Reaction Pathways of CO Electrooxidation in Alkaline Media

摘要

CO electrooxidation at Pt-group catalysts in alkaline media has been first studied in the intermediate temperature range of 80 to 150℃ by means of cyclic voltammetry and chronoamperometry. Accelerated CO electrooxidation reaction kinetics has been achieved in this intermediate temperature. A new pathway involving a formate intermediate formed through the reaction of CO and hydroxide has. been proposed to account for the accelerated kinetics. This is quite different from the CO electrooxidation in alkaline media at low temperature which follows a Langmuir-Hinshelwood (L-H) mechanism. This accelerated CO electrooxidation reaction kinetics would provide fundamentals for the development of fuel cell and hydrogen purification technologies since CO adsorbed on the catalyst surfaces or in bulk solutions can be oxidized at very low potential in the intermediate temperature alkaline media.