Promoting effect of carbon functional groups in methanol oxidation on supported Pt catalyst

The contribution of carbon functional groups (CFG) to methanol oxidation at carbon-supported Pt catalysts is studied in this work. Platinum black, attached in a form of a thin layer to electrochemically treated glassy carbon (GC), is investigated as a model system. Impedance measurements reveal significant changes in capacitive response of GC anodically polarized in H₂SO₄ solution in comparison to unoxidized state. XPS analyses show the increased fraction of oxygen-containing CFGs upon electrochemical treatment of GC. The activity of Pt black attached to oxidized GC for methanol oxidation is more than two times larger in comparison to the catalyst attached to unoxidized GC. Increased activity is most likely due to the promotion of CO_ads removal by increased content of CFGs.