Enhancing Low-Temperature Direct Ammonia Fuel Cell Performance with PtIr/C Catalysts in a Membrane-Electrode Assembly

Direct ammonia fuel cells (DAFCs) are promising energy-conversion devices owing to their high energy densities and ease of storage; however, their application is hindered by the sluggish kinetics of the ammonia oxidation reaction (AOR) and catalyst poisoning. In this study, we systematically investigate the performance of Pt-based catalysts (Pt/C, PtRu/C, and PtIr/C) in the AOR using both half- and single-cell configurations. PtIr/VC with a Pt: Ir ratio different from that of commercial PtIr/C (c-PtIr/C) is synthesized to optimize the Ir utilization. To bridge the gap between half-cell and single-cell configurations, the operating conditions of the membrane-electrode assembly-based single-cell DAFC are optimized, including the anion-exchange membrane, temperature, and conditioning process. Higher temperatures and piperidinium functional groups enhance the DAFC performance. These findings…