Pt Nanowire Arrays on Graphene-Integrated Cathode Gas Diffusion Layer for Proton Exchange Membrane Fuel Cells

The sluggish oxygen reduction reaction (ORR) at the cathode of proton exchange membrane fuel cells (PEMFCs) remains the primary challenge, limiting their performance and durability. This study explores the integration of one-dimensional (1D) platinum nanowires (Pt NWs) with graphene and carbon black (CB) as a promising solution. Varied configurations of graphene and CB are deposited onto the gas diffusion layer (GDL), followed by the growth of 1D Pt NW arrays to form efficient electrodes. Scanning electron microscopy confirms the formation of similar Pt NW array structures across various support configurations. Performance testing in a gas diffusion electrode (GDE) half-cell with 0.1 M HClO4 reveals that the Pt NW electrode supported by a hybrid graphene-CB structure exhibits superior ORR activity, nearly 2-fold the performance of the same configuration electrode supported solely by graphene and the benchmark Pt/C. After 5000 cycles of the accelerated degradation test (ADT), the Pt NW electrodes containing graphene demonstrate better overall durability. Notably, the electrode with only graphene as the support shows superior endurance with just a 4% loss from its initial ORR mass activity. The ADT also reveals the role of graphene in preserving kinetic properties and enhancing electrode stability in the graphene-CB hybrid configuration. Further evaluation under real fuel cell operating conditions using a membrane electrode assembly single-cell test is also performed to assess the electrode’s performance.