Role of Surface Iron in Enhanced Activity for the Oxygen Reduction Reaction on a Pd3Fe(111) Single-Crystal Alloy

摘要

Applications of polymer electrolyte membrane fuel cells (PEM-FCs) require a continued search for an optimal catalyst with attributes of high activity, durability, low cost, and resistance to negative effects of impurities in the fuel. Platinum-based bimetallic catalyst systems are widely utilized in PEM-FCs because of their good performance in both the cathode and the anode. Alloying with inexpensive metals can reduce the loading of platinum and lower the cost of the fuel cell, and in some cases the catalytic activity is maintained or even becomes higher. Surprisingly, some non-platinum-based alloy catalysts (e.g., palladium-iron and palladium-cobalt) appear to have even better performance than platinum-based alloy catalysts.