Thin Film Platinum Alloys For Use As Catalyst Materials In Fuel Cells

摘要

Measurements of the structural and electrochemical properties of nanostructured thin film alloys in the ternary series Pt-Co-Zr are presented. These alloys have been studied to determine the influence of early transition metal element additions on the catalytic response and chemical stability of platinum-group-metal (PGM) alloys in acid electrolytes. The thin film compositions in the Pt-Co-Zr system were prepared via co-sputtering and the films exhibit a (111) crystallographic orientation. Alloys with Pt-metal contents of less than 50 At. % are stable in 0.1 M perchloric acid electrolytes, and are electrochemically active for the oxygen reduction reaction (ORR). The ORR kinetic currents at 0.9 V are comparable to Pt. The alloys have been cycled over the range 0.0 to 1.2 V NHE, with no degradation of the electrode surface area or decrease in electrochemical performance observed. Our results suggest that Pt-Co-Zr alloys with reduced PGM contents may be competitive with Pt-catalysts.