Enhancing H<sub>2</sub>O<sub>2</sub> Electrosynthesis at Industrial-Relevant Current in Acidic Media on Diatomic Cobalt Sites
Helai Huang, Mingze Sun, Shuwei Li, Shengbo Zhang, Yiyang Lee, Zhengwen Li, Jinjie Fang, Chengjin Chen, Yu‐Xiao Zhang, Yanfen Wu, Yizhen Che, Shuairen Qian, Wei Zhu, Cheng Tang, Zhongbin Zhuang, Liang Zhang, Zhiqiang Niu
Abstract
Electrocatalytic synthesis of hydrogen peroxide (H 2 O 2 ) in acidic media is an efficient and eco-friendly approach to produce inherently stable H 2 O 2, but limited by the lack of selective and stable catalysts under industrial-relevant current densities. Herein, we report a diatomic cobalt catalyst for two-electron oxygen reduction to efficiently produce H 2 O 2 at 50–400 mA cm –2 in acid. Electrode kinetics study shows a >95% selectivity for two-electron oxygen reduction on the diatomic cobalt sites. In a flow cell device, a record-high production rate of 11.72 mol g cat –1 h –1 and exceptional long-term stability (100 h) are realized under high current densities. In situ spectroscopic studies and theoretical calculations reveal that introducing a second metal into the coordination sphere of the cobalt site can optimize the binding strength of key H 2 O 2 intermediates due to the downshifted d-band center of cobalt. We also demonstrate the feasibility of processing municipal plastic wastes through decentralized H 2 O 2 production.