Highly dispersed and ultrafine Co3O4@N-doped carbon catalyst derived from metal-organic framework for efficient oxygen reduction reaction

Abstract

Electrocatalysts are composed of transition metal/metal oxide and N-doped carbon can overcome the sluggish kinetics of oxygen reduction reaction (ORR). Herein, The Co3O4/ketjen black (KB) @MOF-derived with uniformly dispersed and ultrafine Co3O4 nanoparticles (1-5 nm) is synthesized by a facile in-suit method and subsequent mild pyrolysis process. It exhibits enhanced activity with onset potential (Eonset) of 0.96 V (vs. RHE) and a half-wave potential (E1/2) of 0.86 V (vs. RHE) in 0.1 M KOH solution, the excellent durability with E1/2 a small negative shift of 10 mV after 5000 continuous cycles and good methanol-tolerance property. The ultrahigh catalytic performance of Co3O4/KB@MOF-derived can be ascribed to the small particle size range of 1-5 nm of Co3O4, as well as the strong interaction between the in-situ formed N-Co3O4 active sites and substrate under the mild calcination temperature. Above all, these indicate that the as-prepared Co3O4/KB @MOF-derived may be a good alternative to commercial Pt-based catalysts.