Nitrogen and Carbon Co-Doped CoOx Nanostructures for Oxygen Reduction

Although precious metal Pt-based cathodic nanomaterials are extensively considered as the excellent electrocatalysts for overcoming sluggish kinetics in oxygen reduction reaction (ORR), their practical applications are severely impeded by high price, low earth abundance, and poor durability of Pt. Hence, it is highly desired to explore cheaper alternatives with comparable catalytic activity and durability for ORR. Herein, the high-efficiency Co–N–C catalyst, composed of CoOx and N-doped carbon, is successfully constructed by pyrolysis of bimetallic CoZn microspheres and polydopamine (PDA). The N-rich PDA could confer plentiful well-distributed Co–Nx, pyridinic N active sites, and abundant hierarchical pores to the catalyst during pyrolysis. The optimal NC/CoN-2 catalyst manifests an E1/2 of 0.818 V and a JL of 5.27 mA/cm2, as well as excellent MeOH tolerance, long-time durability, and the 4e– reaction pathway in alkaline media. Such a remarkable ORR performance of NC/CoN-2 is attributed to the simultaneous compositional (Co/N co-doping) and structural tailoring (micropore/mesopore/macropore), enabled by PDA surface coating.