An XPS study on binary and ternary alloys of transition metals with platinized carbon and its bearing upon oxygen electroreduction in direct methanol fuel cells

The present X-ray photoelectron spectroscopic study on carbon-supported Pt, Pt–Cr, Pt–Co, Pt–Ni, Pt–Co–Cr and Pt–Co–Ni electrocatalysts suggests that while Pt–Cr/C, Pt–Co/C and Pt–Ni/C binary alloy electrocatalysts are surface rich in platinum, both Pt–Co–Cr/C and Pt–Co–Ni/C ternary electrocatalysts happen to be surface rich in base metals. Among these electrocatalysts, Pt–Co/C electrocatalyst is found to possess a minimum amount of platinum oxides. Accordingly, Pt–Co/C exhibits a higher electrocatalytic activity towards oxygen-reduction reaction in the solid-polymer-electrolyte direct methanol fuel cells.