Constructing CoFe alloy and tailoring d-band center in trimetallic ZIF-derived porous carbon for bifunctional oxygen electrocatalysis

Synthesis of multiple-site single-atom catalyst (SAC) with metal-containing nanoparticles by using zeolite imidazole framework (ZIF) for improving the bifunctional electrocatalytic performance is of great significance, yet it is also a challenge. Trimetallic ZIF-derived porous carbon nanosheets with the CoFe alloy nanoparticles enclosed in nitrogen-doped carbon nanotubes (N-CNTs) are fabricated by utilizing three transition metals as ZIF precursors and sodium chloride as templates via a typical two-step process, including synthesis and pyrolysis. By building CoFe alloy and tailoring d-band center ( E d ) of the Co site, the as-obtained FeCoZn@S-CN ZIF exhibits predominant kinetic activity and durability towards ORR and OER with an extremely low potential gap (Δ E ) value of 0.584    V, exceeding many other efficient counterparts. This study provides an effective approach for designing and synthesizing atomically dispersed multi-metal site catalysts with alloyed nanoparticles to achieve high-efficient bifunctional electrocatalytic performance in the application of the recharged zinc-air battery (ZAB).