High‐efficiency Electroreduction of O2 into H2O2 over ZnCo Bimetallic Triazole Frameworks Promoted by Ligand Activation

Abstract

AbstractCo‐based metal–organic frameworks (MOFs) as electrocatalysts for two‐electron oxygen reduction reaction (2e− ORR) are highly promising for H2O2 production, but suffer from the intrinsic activity‐selectivity trade‐off. Herein, we report a ZnCo bimetal‐triazole framework (ZnCo‐MTF) as high‐efficiency 2e− ORR electrocatalysts. The experimental and theoretical results demonstrate that the coordination between 1,2,3‐triazole and Co increases the antibonding‐orbital occupancy on the Co−N bond, promoting the activation of Co center. Besides, the adjacent Zn−Co sites on 1,2,3‐triazole enable an asymmetric “side‐on” adsorption mode of O2, favoring the reduction of O2 molecules and desorption of OOH* intermediate. By virtue of the unique ligand effect, the ZnCo‐MTF exhibits a 2e− ORR selectivity of ≈100 %, onset potential of 0.614 V and H2O2 production rate of 5.55 mol gcat−1 h−1, superior to the state‐of‐the‐art zeolite imidazole frameworks. Our work paves the way for the design of 2e− ORR electrocatalysts with desirable coordination and electronic structure.