Preparation, performance and stability of Fe-N-C catalyst membrane electrode by gas diffusion method for oxygen reduction

The performance of proton exchange membrane fuel cell (PEMFC) is significantly influenced by membrane electrode assembly(MEA), in which the structure of the cathode catalyst layer (CCL) plays a critical role in determining overall efficiency and stability. Although Fe-N-C non-precious metal catalysts have been extensively studied for their promising oxygen reduction reaction (ORR) activity, they still face key challenges such as poor durability, limited mass transport, and low utilization of active sites. In this study, a self-fabricated Fe-N-C catalyst was employed to construct a porous CCL using the gas diffusion electrode (GDE) method. The MEA was prepared under optimized conditions of I/C ratio of 0.6 and catalyst loading of 3.5mg/cm^2. Electrochemical testing revealed the current retention rates were 88.39% and 81.01% after 10 hours and 20 hours of operation, respectively. Power density decay rates were 8.40% after 5000 AST cycles and 29.04% after 30000 cycles. The GDE-fabricated CCL significantly enhanced internal mass transport efficiency, achieving peak power densities of 940mW/cm² (H₂-O₂) and 434mW/cm² (H₂-air). These results highlighted the advantages of the GDE approach over the conventional CCM method, and provided new ideas and support for the optimization design of non-precious metal catalysts and the development of high-performance PEMFC.