Combinatorial screening of highly active Pd binary catalysts for electrochemical oxygen reduction.

Electro-catalysts omitting platinum are of interest to reduce the cost of fuel cells. The development of non-Pt alloys for this purpose would require a large number of experiments. Palladium-based bimetallic electro-catalysts using eight different metals were computationally evaluated for the oxygen reduction reaction (ORR) and were made and tested in acidic media using combinatorial methods. A Pd-Co alloy showed the closest oxygen adsorption energy to platinum in simple theoretical model calculations, suggesting the highest ORR activity. This prediction was confirmed experimentally, suggesting that the single parameter of oxygen adsorption energy can be a useful guide to developing non-Pt oxygen reduction catalysts in the future.