High‐efficiency Electroreduction of O<sub>2</sub> into H<sub>2</sub>O<sub>2</sub> over ZnCo Bimetallic Triazole Frameworks Promoted by Ligand Activation
Zimeng Li, Chaoqi Zhang, Chao Liu, Hongwei Zhang, Hao Song, Zhiqiang Zhang, Guangfeng Wei, Xiaojun Bao, Chengzhong Yu, Pei Yuan
Abstract
Abstract Co‐based metal–organic frameworks (MOFs) as electrocatalysts for two‐electron oxygen reduction reaction (2e − ORR) are highly promising for H 2 O 2 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 O 2 , favoring the reduction of O 2 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 H 2 O 2 production rate of 5.55 mol g cat −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.