Modulation of protons and cations at the electrode–electrolyte interface for effective selectivity of ammonia production during electrochemical nitrate reduction reaction

▌Modulation of protons and cations at the electrode–electrolyte interface for effective selectivity of ammonia production during electrochemical nitrate reduction reaction
調控電極–電解液界面的質子與陽離子以提升電化學硝酸根還原反應的產氨選擇性

Jou-Chun Lin, Meng-Chi Hsieh, Lo-Yu Lee, Yi-Cheng Su, Yi-Chia Chen, Yung-Yi Huang, Cheng-Chi Xiao, Chueh-Cheng Yang, Chun-Chih Chang*, Chia-Hsin Wang* and Di-Yan Wang*
https://doi.org/10.1016/j.apcatb.2026.126786
SEED Member: Di-Yan Wang

Schematic comparison of NO₃⁻, Na⁺ and H⁺ at the Cu catalyst interface in different electrolytes

Major Contributions

1. Systematically investigated how sodium ions (Na⁺) and protons (H⁺) compete at the electrode–electrolyte interface and govern electrochemical nitrate reduction (NO3RR) on copper nanodendrites in NaNO₃, HNO₃ and mixed electrolytes.

2. In situ near-ambient-pressure XPS and molecular dynamics show that Na⁺ adsorbs competitively on the Cu surface, suppressing NO₃⁻ binding, raising the overpotential and favoring nitrite formation between +0.2 and −0.2 V vs RHE.

3. H⁺ promotes NO₃⁻ adsorption even without applied potential and markedly increases NH₃ selectivity and yield, especially at 0.01 M nitrate, explaining the high overpotential in neutral media.

主要貢獻

1. 系統探討鈉離子（Na⁺）與質子（H⁺）在電極–電解液界面的競爭，及其如何影響銅奈米樹枝晶在不同電解液（NaNO₃、HNO₃ 及兩者混合）中的硝酸根還原反應。

2. 臨場近常壓 X 光光電子能譜與分子動力學模擬顯示，Na⁺ 競爭吸附於銅表面、抑制 NO₃⁻ 鍵結，使過電位升高，並在 +0.2 至 −0.2 V vs RHE 間偏向生成亞硝酸根。

3. H⁺ 在未施加電位時即可促進 NO₃⁻ 吸附，顯著提升 NH₃ 選擇性與產率，在 0.01 M 低濃度硝酸根下尤其明顯；此結果也說明中性介質中過電位偏高的原因。