Thermolytical Entrapment of Ultrasmall MoC Nanoparticles into 3D Frameworks of Nitrogen-Rich Graphene for Efficient Oxygen Reduction

In our efforts to obtain Pt-free oxygen reduction reaction (ORR) electrocatalysts with high efficiency for fuel cell and metal–air battery, design, and preparation of novel materials with desired morphology and active sites are vitally necessary. Herein, a novel MoC-based ORR catalyst with high efficiency is achieved. The proposed catalyst is comprised of ultrasmall-sized MoC nanoparticles (average size ∼ 1.5 nm) entrapped into 3D porous frameworks of N-rich graphene (NGr), which is synthesized by using layered C 3 N 4 as a sacrificial template via a facile pyrolytic approach. Possessing unique structural features (including preferential O 2 absorbing sites, good accessibility, favorable conductive and protective 3D frameworks of NGr), the MoC/NGr catalyst exhibits positive onset- and peak- potential at 0.93 and 0.80 V for ORR in alkaline media with good four-electron selectivity ( n ≈ 4.0), which is promising and even competitive to commercial Pt/C, particularly in terms of cost-effectiveness, the ease of preparation, significantly improved methanol tolerance, and enhanced stability. Other prospective application of MoC/NGr could also be broadened to biomimic catalysis, energy conversion, storage devices, and so on.