Coordination-Asymmetry-Regulated Reconstruction of Electron-Rich Cu Sites for pH-Dependent Nitrate-to-Ammonia Electrocatalysis.
5 affiliations
- 1Scientific Research Division, National Synchrotron Radiation Research Center, Hsinchu, Taiwan.
- 2Department of Chemistry, National Taiwan University, Taipei, Taiwan.
- 3Department of Materials Science and Engineering, National Yang Ming Chiao Tung University, Hsinchu, Taiwan.
- 4Department of Materials Science and Engineering, National Tsing Hua University, Hsinchu, Taiwan.
- 5Experimental Facility Division, National Synchrotron Radiation Research Center, Hsinchu, Taiwan.
Abstract
Electrocatalytic nitrate reduction reaction (e-NO₃RR) offers a promising route to valorize nitrate-contaminated wastewater while enabling sustainable ammonia production; however, how local coordination asymmetry regulates Cu-site evolution and reaction pathways across different pH environments remains insufficiently understood. Herein, three- and four-nitrogen-coordinated Cu single-atom motifs, denoted as Cu─N₃ and Cu─N₄, are constructed as well-defined pre-catalyst models to elucidate how the initial Cu coordination environment directs pH-dependent active-site reconstruction. Operando X-ray absorption spectroscopy and wavelet-transform EXAFS reveal that Cu─N₄ readily undergoes rapid reconstruction under acidic, neutral, and alkaline conditions, generating low-coordinated, electron-enriched Cu species while concomitantly inducing Cu─Cu aggregation and excessive Cu─site reduction. In contrast, Cu─N₃ displays more regulated site evolution, with limited activation under acidic conditions but progressive formation of low-coordinated Cu─Nx active structures under neutral and alkaline conditions. In situ ATR-FTIR further verifies that the dynamically evolved Cu─N₃ sites enhance nitrate adsorption, facilitate N─O bond activation, and promote the formation of hydrogenated nitrogen intermediates. These findings establish coordination-governed site evolution as a design principle for balancing productive Cu─site activation and metal-centered over-reduction, providing molecular-level guidance for the design of pH-adaptive NO₃RR catalysts.
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BibTeX
@article{huang2026coordinationasymmetryregulated,
title = {{Coordination-Asymmetry-Regulated Reconstruction of Electron-Rich Cu Sites for pH-Dependent Nitrate-to-Ammonia Electrocatalysis.}},
author = {Shih-Ching Huang and Yu-Ru Lin and Hsiang-Chun Yu and Yi-Dong Lin and Yu-Chiao Chang and Chun-Kuo Peng and Yu-Chang Lin and Wen-Wei Wu and Hao Ming Chen and Chi-Liang Chen and Han-Yi Chen and Yan-Gu Lin},
journal = {Advanced science (Weinheim, Baden-Wurttemberg, Germany)},
year = {2026},
month = oct,
doi = {10.1002/advs.78164},
url = {https://europepmc.org/article/MED/42875820},
note = {CC BY},
}
RIS
TY - JOUR
TI - Coordination-Asymmetry-Regulated Reconstruction of Electron-Rich Cu Sites for pH-Dependent Nitrate-to-Ammonia Electrocatalysis.
AU - Shih-Ching Huang
AU - Yu-Ru Lin
AU - Hsiang-Chun Yu
AU - Yi-Dong Lin
AU - Yu-Chiao Chang
AU - Chun-Kuo Peng
AU - Yu-Chang Lin
AU - Wen-Wei Wu
AU - Hao Ming Chen
AU - Chi-Liang Chen
AU - Han-Yi Chen
AU - Yan-Gu Lin
PY - 2026
DA - 2026/10/14
JO - Advanced science (Weinheim, Baden-Wurttemberg, Germany)
DO - 10.1002/advs.78164
UR - https://europepmc.org/article/MED/42875820
AB - Electrocatalytic nitrate reduction reaction (e-NO₃RR) offers a promising route to valorize nitrate-contaminated wastewater while enabling sustainable ammonia production; however, how local coordination asymmetry regulates Cu-site evolution and reaction pathways across different pH environments remains insufficiently understood. Herein, three- and four-nitrogen-coordinated Cu single-atom motifs, denoted as Cu─N₃ and Cu─N₄, are constructed as well-defined pre-catalyst models to elucidate how the initial Cu coordination environment directs pH-dependent active-site reconstruction. Operando X-ray absorption spectroscopy and wavelet-transform EXAFS reveal that Cu─N₄ readily undergoes rapid reconstruction under acidic, neutral, and alkaline conditions, generating low-coordinated, electron-enriched Cu species while concomitantly inducing Cu─Cu aggregation and excessive Cu─site reduction. In contrast, Cu─N₃ displays more regulated site evolution, with limited activation under acidic conditions but progressive formation of low-coordinated Cu─Nx active structures under neutral and alkaline conditions. In situ ATR-FTIR further verifies that the dynamically evolved Cu─N₃ sites enhance nitrate adsorption, facilitate N─O bond activation, and promote the formation of hydrogenated nitrogen intermediates. These findings establish coordination-governed site evolution as a design principle for balancing productive Cu─site activation and metal-centered over-reduction, providing molecular-level guidance for the design of pH-adaptive NO₃RR catalysts.
SN - 2198-3844
ER -