Linker-Compensated Metal-Organic Framework with ElectronDelocalized Metal Sites for Bifunctional Oxygen Electrocatalysis

Metal-organic frameworks with tailorable coordinationchemistry are propitious for regulating catalytic performance anddeciphering genuine mechanisms. Herein, a linker compensation strategyis proposed to alter the intermediate adsorption free energy on the Co-Fezeolitic imidazolate framework (CFZ). This grants zinc-air batterysuperior high current density capability with a small discharge-chargevoltage gap of 0.88 V at 35 mA cm-2and an hourly fading rate of less than0.01% for over 500 h. Systematic characterization and theoretical modelingreveal that the performance elevation is closely correlated with thecompensation of CFZ unsaturated metal nodes by S-bridging heteroge-neous linkers, which exhibit electron-withdrawing characteristic that drivesthe delocalization of d-orbital electrons. These rearrangements ofelectronic structures establish a favorable adsorption/desorption pathwayfor key intermediates (OH*) and a stable coordination environment in bifunctional oxygen electrocatalysis.

Automated summary

This study proposes a linker compensation strategy to enhance the catalytic performance of metal-organic frameworks. By compensating the metal nodes, the performance of zinc-air batteries can be improved, resulting in higher current density and more stable voltage gap.