Optimizing Catalyst Loading Ratio between the Anode and Cathode for Ultralow Catalyst Usage in Polymer Electrolyte Membrane Fuel Cell

With increasing demand for high-efficiency and clean energy sources, the polymer electrolyte membrane fuel cell (PEMFC) has received attention in a wide range of fields including transportation and back-up power. For securing the economic viability of PEMFC, the U.S. Department of Energy (DOE) provides the target of the total Pt catalyst loading as 0.125 mg(Pt) cm(-2) on both cathode and anode, which is much less than that currently used (>0.25 mg(Pt) cm(-2) for cathode). An optimized ratio of catalyst loading between the anode and cathode with a fixed Pt catalyst loading according to the DOE target is figured out by conducting diverse electrochemical measurements with varying the catalyst loading ratio in single-cells. Among the experimental set, the membrane electrode assembly (MEA) with 70% catalyst loading on the cathode side shows the highest performance with the maximum power density of 643 mW cm(-2), while the MEA with 90% catalyst loading on the cathode side exhibits inferior performance. Experimental results are validated by suggesting the theoretical model, which was established based on considering both the electrochemical kinetics of hydrogen oxidation and oxygen reduction reaction.