Residual ligand-functionalized ultrathin Ni(OH)2 via reconstruction for high-rate HO2- electrosynthesis

Tianyu Zhang; Weibo Wang; Wenxian Liu; Zhengxiao Guo; Junfeng Liu

doi:10.1038/s41467-025-60467-0

Residual ligand-functionalized ultrathin Ni(OH)₂ via reconstruction for high-rate HO₂^- electrosynthesis

Nat Commun. 2025 Jun 5;16(1):5240. doi: 10.1038/s41467-025-60467-0.

Authors

Tianyu Zhang^#^{1

2

3}, Weibo Wang^#¹, Wenxian Liu⁴, Zhengxiao Guo^{5

6}, Junfeng Liu⁷

Affiliations

¹ State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, Beijing, 100029, China.
² Hong Kong Quantum AI Lab, AIR@InnoHK of Hong Kong Government, Hong Kong SAR, 999077, China.
³ Faculty of Maritime and Transportation, Ningbo University, Ningbo, 315211, China.
⁴ College of Materials Science and Engineering, Zhejiang University of Technology, Hangzhou, 310014, China.
⁵ Hong Kong Quantum AI Lab, AIR@InnoHK of Hong Kong Government, Hong Kong SAR, 999077, China. zxguo@hku.hk.
⁶ Department of Chemistry, The University of Hong Kong, Hong Kong SAR, 999077, China. zxguo@hku.hk.
⁷ State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, Beijing, 100029, China. ljf@mail.buct.edu.cn.

^# Contributed equally.

Abstract

Reconstruction of metal-organic frameworks often occurs under reaction conditions, thereby impeding true active species identification and hindering mechanism understanding. Herein, we present the mechanistic insight underlying the electrochemical synthesis of deprotonated anion of H₂O₂ (HO₂^-) via 2e^- oxygen reduction by ultrathin Ni-benzenedicarboxylic acid (NiBDC), guided by its thickness-dependent performance and pH-induced reconstruction behavior. The real active species are identified as alkaline-reconstructed β-Ni(OH)₂ that is chemically coupled with 1,4-benzenedicarboxylic acid residual ligand. The hybrid catalyst is characterized to exhibit an optimized surface electronic structure, which improves the intrinsic activity and selectivity. Operando characterization and theoretical simulations further reveal that the residual ligand functionalization significantly boosts the formation and facilitates the adequate binding of *OOH intermediates. Thus, the ligand-functionalized Ni(OH)₂ exhibits high HO₂^- selectivity (>90%) in 0.1 M KOH across a broad current density up to 200 mA cm^-2. Moreover, high HO₂^- production rate of 13.7 mol g_cat^-1 h^-1 with significant accumulation of 2.0 wt.% HO₂^- under alkaline conditions is achieved at 200 mA cm^-2 over 100 h, suggesting the promising potential for large-scale electrosynthesis of HO₂^- in industrial applications.