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

• Published in: Angewandte Chemie International Edition Vol. 63; no. 2
• Main Authors: Li, Zi‐Meng, Zhang, Chao‐Qi, Liu, Chao, Zhang, Hong‐Wei, Song, Hao, Zhang, Zhi‐Qiang, Wei, Guang‐Feng, Bao, Xiao‐Jun, Yu, Cheng‐Zhong, Yuan, Pei
• Format: Journal Article
• Language: English
• Published: Weinheim Wiley Subscription Services, Inc 08.01.2024
• Edition: International ed. in English
• Subjects: Bimetals; Chemical reduction; Coordination; Electrocatalysts; Electronic structure; Hydrogen peroxide; Imidazole; Ligand effect; Ligands; Metal-organic frameworks; metal-triazole framework; metal–organic framework; Oxygen reduction reactions; Triazoles; Two electron oxygen reduction; Zeolites
• ISSN: 1433-7851; 1521-3773
• DOI: 10.1002/anie.202314266

Co‐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. A ZnCo bimetal‐triazole framework has been developed as high‐efficiency 2e− ORR electrocatalysts. The unique ligand effect of 1,2,3‐triazole optimizes the electronic structure of Co sites and enables an asymmetric “side‐on” adsorption mode of O2 molecule, resulting in an excellent 2e− ORR performance with a selectivity of ≈100 % and an H2O2 production rate of 5.55 mol gcat−1 h−1.