Reduced graphene oxide intercalated Co₂C or Co₄N nanoparticles as an efficient and durable fuel cell catalyst for oxygen reduction

Research on catalysis for fuel cells is extremely important to enhance the sluggish oxygen reduction reaction (ORR) using heterogeneous catalyst materials. In this work, cobalt carbide (Co₂C) and cobalt nitride (Co₄N) nanoparticles were intercalated with reduced graphene oxide (rGO) sheets through heteroatom doping and utilized for the ORR in alkaline fuel cells, in which rGO acted as a catalyst support. Cyclic voltammetry results indicated that the ORR half-wave potentials of Co₂C/rGO and Co₄N/rGO were found to be −0.095 V and −0.118 V, respectively. Chronoamperometric studies revealed the excellent catalytic stability of the prepared catalysts. The reaction kinetics study showed that Co₂C/rGO and Co₄N/rGO pursued a 4e⁻ (four electron) oxygen reduction process. The catalytic activity and stability in alkaline electrolyte indicated that Co₂C/rGO and Co₄N/rGO have great potential as alternatives to precious metal-based catalysts.