近日，中国科技大学曾杰团队实现了固定化唑层调界面氢源用于强酸中CO₂电还原。这一研究成果发表在2025年8月27日出版的《美国化学会志》上。

在强酸中实现选择性电化学CO₂还原反应（CO₂RR）有望解决“碳酸盐形成”问题，但仍受到析氢反应（HER）的阻碍。不同氢强度（即H⁺ vs H₂O）之间的相互作用及其对酸性电解质中CO₂RR选择性的影响仍然知之甚少。

研究组在Bi催化剂上引入固定化含氮唑层（phTA），以动态调节强酸（pH 0.4）下的界面氢强度。结合实验和建模方法，他们揭示了依赖于局部界面条件的双重机制。在具有高局部[H⁺]的低电位下，质子化的phTA层（NH⁺位点）充当质子继电器，同时静电屏蔽体H⁺扩散。

相反，在具有低局部[H⁺]的高电位下，较少质子化的phTA破坏了界面氢键网络，阻碍了groththems型质子传输，通过氢向H₂O转移来抑制HER。因此，在−300 mA cm^–2（pH 0.4）条件下，Bi-phTA电极对甲酸的法拉第效率（FEHCOOH）显著提高至36%，而裸铋电极的法拉第效率不足10%。这项工作证明了通过动态响应的有机层对氢强度的控制，强调了管理界面氢对增强酸中CO₂RR的重要性。

附：英文原文

Title: Immobilized Azole Layer Tunes Interfacial Hydrogen Source for CO2 Electroreduction in Strong Acid

Author: Yaohui Shi, Yu Yang, Aoni Xu, Kwun Nam Hui, Fengwang Li, Jie Zeng

Issue&Volume: August 27, 2025

Abstract: Achieving selective electrochemical CO2 reduction reaction (CO2RR) in strong acid holds potential to resolve the “carbonate formation” problem yet is hindered by the competing hydrogen evolution reaction (HER). The interplay between different hydrogen sources (i.e., H+ vs H2O) and its impact on CO2RR selectivity in acidic electrolytes remains poorly understood. Herein, we introduce an immobilized N-containing azole layer (phTA) onto Bi catalysts to dynamically regulate the interfacial hydrogen source in strong acid (pH 0.4). Combining experimental and modeling approaches, we reveal a dual mechanism dependent on local interfacial conditions. At lower potentials with high local [H+], the protonated phTA layer (NH+ sites) serves as a proton relay while electrostatically shielding bulk H+ diffusion. Conversely, at higher potentials with low local [H+], less protonated phTA disrupts the interfacial hydrogen-bond network, impeding Grotthuss-type proton transport, thus suppressing HER through hydrogen source shifts toward H2O. As a result, the faradaic efficiency for formic acid (FEHCOOH) on Bi-phTA significantly increases to 36% at 300 mA cm–2 (pH 0.4) compared to <10% for bare Bi. This work demonstrates the controlled manipulation of the hydrogen source via a dynamically responsive organic layer, highlighting the importance of managing interfacial hydrogen species for enhancing the CO2RR in acid.

DOI: 10.1021/jacs.5c11829

Source: https://pubs.acs.org/doi/abs/10.1021/jacs.5c11829