Atomically dispersed asymmetric cobalt electrocatalyst for efficient hydrogen peroxide production in neutral media

Electrochemical hydrogen peroxide (H2O2) production (EHPP) via a two-electron oxygen reduction reaction (2e ORR) provides a promising alternative to replace the energy-intensive anthraquinone process. M-N-C electrocatalysts, which consist of atomically dispersed transition metals and nitrogen-doped carbon, have demonstrated considerable EHPP efficiency. However, their full potential, particularly regarding the correlation between structural configurations and performances in neutral media, remains underexplored. Herein, a series of ultralow metal-loading M-N-C electrocatalysts are synthesized and investigated for the EHPP process in the neutral electrolyte. CoNCB material with the asymmetric Co-C/N/O configuration exhibits the highest EHPP activity and selectivity among various as-prepared M-N-C electrocatalysts, with an outstanding mass activity (6.1 × 10^5 A gCo−1 at 0.5 V vs. RHE), and a high practical H2O2 production rate (4.72 molcatalyst−1 h−1 cm−2). Compared with the popularly recognized square-planar symmetric Co-N4 configuration, the superiority of asymmetric Co-C/N/O configurations is elucidated by X-ray absorption fine structure spectroscopy analysis and computational studies.

Longxiang Liu, Liqun Kang, Jianrui Feng, David G. Hopkinson, Christopher S. Allen, Yeshu Tan, Hao Gu, Iuliia Mikulska, Veronica Celorrio, Diego Gianolio, Tianlei Wang, Liquan Zhang, Kaiqi Li, Jichao Zhang, Jiexin Zhu, Georg Held, Pilar Ferrer, David Grinter, June Callison, Martin Wilding, Sining Chen, Ivan Parkin, Guanjie He