Conductive Two-Dimensional Magnesium Metal–Organic Frameworks for High-Efficiency O<sub>2</sub> Electroreduction to H<sub>2</sub>O<sub>2</sub>
Kai Dong, Jie Liang, Yuanyuan Wang, Longcheng Zhang, Zhaoquan Xu, Shengjun Sun, Yongsong Luo, Tingshuai Li, Qian Liu, Na Li, Bo Tang, Abdulmohsen Ali Alshehri, Quan Li, Dongwei Ma, Xuping Sun
Abstract
Direct electrosynthesis of H2O2 via a two-electron oxygen reduction reaction (2e– ORR) under ambient conditions is emerging as a promising solution toward on-site applications for the replacement of the energy-consuming, waste-intensive, and indirect anthraquinone process. To date, state-of-the-art 2e– ORR catalysis is mostly performed with transition-metal-based materials, while main-group element-based catalysts are much less established, for which there is an urgent need of proper understanding. Herein, we report a conductive two-dimensionally layered Mg3(hexaiminotriphenylene)2 electrocatalyst for selective hydrogenation of O2 to synthesize H2O2 (selectivity >90%) with a robust high catalytic efficiency. In situ spectroscopic monitoring of the catalytic reactions and kinetic studies not only illustrate the reaction mechanisms on Mg3(hexaiminotriphenylene)2 but confirm that the Mg2+ center serving as the real active site is responsible for the critical intermediate OOH* forming event. Additionally, in-depth density functional theory calculations further discuss the excellent activity and selectivity of Mg3(hexaiminotriphenylene)2 for H2O2 production.