Catalyst-Engineered Proton Transfer Pathways for Selective Pure Hydrogen Peroxide Electrosynthesis in Solid-State Electrolytes

Jun Wang; Junheng Huang; Chunguang Jia; Wenxing Chen; Junxiang Chen; Shengjian Lin; Yangjie Liu; Kai Chen; Yiqi Liang; Suqin Ci; Zhenhai Wen

doi:10.1002/anie.202510645

Catalyst-Engineered Proton Transfer Pathways for Selective Pure Hydrogen Peroxide Electrosynthesis in Solid-State Electrolytes

Angew Chem Int Ed Engl. 2025 Jun 26:e202510645. doi: 10.1002/anie.202510645. Online ahead of print.

Authors

Affiliations

¹ Chinese Academy of Sciences Fujian Institute of Research on the Structure of Matter, FJIRSM, CHINA.
² Nanchang Hangkong University, Key Laboratory of Jiangxi Province for Persistent Pollutants Control and Resources Recycle, CHINA.
³ Beijing Institute of Technology, Department of Chemical Engineering, CHINA.
⁴ Fujian Institute of Research on the Structure of Matter, Chinese Academy of Science, Institute of Materials, 155 Yangqiao Road West, 350002, Fuzhou, CHINA.

PMID: 40571655
DOI: 10.1002/anie.202510645

Abstract

Polymer-based solid electrolyte (SE) cells hold great promise for electrochemical synthesis of pure H2O2, yet the protonation mechanisms governing the two-electron oxygen reduction reaction (2e--ORR) in such systems, particularly when using pure water as the proton source, remain unclear. While both Langmuir-Hinshelwood (LH, surface *H-mediated) and Eley-Rideal (ER, water-derived proton-coupled) pathways are theoretically plausible, their practical dominance under SE conditions has locked experimental validation. Herein, we designed a hierarchical Ni-N2-C-O single-atom/NiO nanocluster co-decorated porous carbon nanosheet catalyst (NiSA-NiO/pCNs) that achieved exceptional 2e--ORR performance, achieving a Faradaic efficiency of 97% and a H2O2 partial current density of 356 mA cm-2 (equivalent to 6.6 mmol cm-2 h-1 production rate) in a membrane-free SE cell. Through detailed analysis of reaction intermediates and the local pH using in-situ Raman spectroscopy, kinetic isotope effect and density functional theory simulations, we demonstrated the critical role of NiO nanoclusters in tuning the protonation pathway: the water dissociation (WD) capability of NiO activates the ER mechanism via fast proton transfer from solvent water, whereas NiSA/pCNs without NiO preferentially follow the LH mechanism through surface-adsorbed *H intermediates from the interfacial transferred proton. These findings establish a catalyst design principle for controlling interfacial proton transfer routes in solid-state H2O2 electrosynthesis.

Keywords: Two-electron Oxygen Reduction Reaction * Membrane-free Solid Electrolyte * Pure Hydrogen Peroxide * Proton Transfer Pathways.