A dual metal-organic framework strategy for synthesis of FeCo@NC bifunctional oxygen catalysts for clean energy application

Developing high efficient bifunctional oxygen electrocatalysts for clean energy applications like Zin-air battery (ZAB) is highly desired, because it would reduce the cost and speed up the practical application of ZAB. Here we use a dual metal-organic framework (MOF) synthesis strategy to prepare the N-doped carbon supported bimetallic FeCo nanoparticle catalysts (marked as FeCo@NC) by pyrolysis of ZnCoZIF/MIL-101(Fe) composite. The FeCo@NC exhibits remarkable electrocatalytic activity for ORR with half-wave potential of 0.89 V vs. the reversible hydrogen electrode (RHE) and robust durability for both ORR and OER (oxygen reduction reaction and oxygen evolution reaction), which is attributed to the generation of Fe0.26Co0.74 crystalline phase and mesopores due to the dual-MOF synthesis strategy. The rechargeable ZAB based on FeCo@NC air electrode shows a maximum energy density of 139.6mW. cm(-2) and excellent cyclic stability over 130 h, significantly surpassing the Pt and Ir-based ZAB. The present work provides a useful dual-MOF synthesis strategy for preparing high-performance multifunctional catalysts for ORR, OER and hydrogen evolution reaction (HER). (C) 2022 The Chemical Industry and Engineering Society of China, and Chemical Industry Press Co., Ltd. All rights reserved.