Linker-Compensated Metal–Organic Framework with Electron Delocalized Metal Sites for Bifunctional Oxygen Electrocatalysis
Yi Jiang, Ya‐Ping Deng, Ruilin Liang, Ning Chen, Graham King, Aiping Yu, Zhongwei Chen
Abstract
Metal–organic frameworks with tailorable coordination chemistry are propitious for regulating catalytic performance and deciphering genuine mechanisms. Herein, a linker compensation strategy is proposed to alter the intermediate adsorption free energy on the Co–Fe zeolitic imidazolate framework (CFZ). This grants zinc–air battery superior high current density capability with a small discharge–charge voltage gap of 0.88 V at 35 mA cm–2 and an hourly fading rate of less than 0.01% for over 500 h. Systematic characterization and theoretical modeling reveal that the performance elevation is closely correlated with the compensation of CFZ unsaturated metal nodes by S-bridging heterogeneous linkers, which exhibit electron-withdrawing characteristic that drives the delocalization of d-orbital electrons. These rearrangements of electronic structures establish a favorable adsorption/desorption pathway for key intermediates (OH*) and a stable coordination environment in bifunctional oxygen electrocatalysis.