One-Pot Room Temperature Synthesis of Nitrogen-Doped Graphene and Its Application as Catalyst Support for ORR in PEMFCs

Catalyst durability is one of the crucial factors for the large-scale commercialization of proton-exchange membrane fuel cells (PEMFCs). Graphene is a potential candidate for catalyst support, among the various alternatives, owing to its excellent properties, such as high surface area and stability. Its large-scale employment has, however, been limited due to the difficulties involved in production and maintaining optimal functional groups for Pt incorporation without compromising its innate stability. In this work, we synthesized functionalized multilayer graphene with in situ nitrogen doping using a simple, one-step electrochemical process at room temperature with an eco-friendly nitrogen source. We investigated various parameters, such as electrolyte concentrations, synthesis conditions, and the need for post-exfoliation procedures to produce the optimized support. Nitrogen doping up to 10 at. % was obtained by increasing precursor concentration. Pt incorporation was performed using an ultrafast microwave-assisted polyol process. Uniform distribution with an average particle size <2 nm was obtained on the optimized support. When tested for activity toward the oxygen reduction reaction (ORR) in acidic media, the catalysts exhibited higher onset potential and mass activity than the commercial Pt/C catalyst. Accelerated degradation tests revealed higher electrochemically active surface area retention for the synthesized catalyst compared to commercially available Pt/C.