Bimetallic metal-organic-framework-derived porous cobalt manganese oxide bifunctional oxygen electrocatalyst

This work reports a novel ligand-enabled strategy to incorporate dual metals into metal–organic-framework-derived bifunctional oxygen electrocatalysts. The involvement of bimetallic systems helps to reduce the necessity for critical raw materials while enhancing the overall electroactivity of the catalyst. Herein, we introduce a unique mixed-metal manganese/cobalt metal–organic framework (TAL-42) as a versatile single precursor for the facile preparation of highly efficient bifunctional oxygen electrocatalysts. Rotating disk electrode (RDE) experiments in 0.1 M KOH demonstrated that forming the heterogeneous bimetallic surface with metal-Nx functionalities results in an excellent bifunctional performance toward oxygen reduction/evolution reaction. The TAL-42–900 material exhibited superior bifunctional ORR/OER performance (ΔE = 0.80 V) to commercial Pt/C + RuO2 catalyst (ΔE = 0.84 V). In a rechargeable zinc-air battery test, the TAL-42–900 air cathode possessed excellent efficiency with a maximum power density of 155 mW cm−2 without degradation over prolonged cycling.