南京航空航天大学彭生杰研究团队报道了吸附物相互作用下，电催化CO₂还原气液产物的反应途径调控。相关研究成果发表在2024年12月9日出版的《德国应用化学》。

过渡金属上的卤化物阴离子吸附可以提高电化学CO₂还原反应（CO₂RR）的性能，但控制选择性CO₂RR途径的具体反应机制尚不清楚。

该文中，研究人员首次证明了气态（CO）和液态产物（甲酸盐和乙醇），在具有控制氯化作用的明确Ag-Cu纳米结构上的不同途径。研究发现，通过调节AgCl层的厚度，可以调节Ag/AgCl上CO₂转化为CO，使用流动池在0.5 M KHCO₃的宽电位范围内，实现接近100%的法拉第效率（FE）。

相比之下，在类似条件下提供高电流密度，优化的Cl-Ag/Cu系统能够将CO₂转化为液体产物，包括甲酸盐和乙醇，总FE接近100%。原位红外实验和理论计算表明，*OCHO中间体的横向吸附物，通过降低每个潜在极限步骤的吉布斯自由能垒，促进了Cl-Ag（111）上CO途径和Cl-Ag/Cu（111）下甲酸盐途径的热力学。

该项工作揭示了氯化在Ag-Cu催化剂上CO₂RR过程中，调节C结合或O结合中间体的作用，确定了横向吸附物效应下的反应途径。

附：英文原文

Title: Reaction Pathway Regulation for Gaseous and Liquid Products of Electrocatalytic CO2 Reduction under Adsorbate Interactions

Author: Feng Hu, Xiaoqian Xu, Yajie Sun, Chuan Hu, Shuning Shen, Ying Wang, Lei Gong, Linlin Li, Shengjie Peng

Issue&Volume: 2024-12-09

Abstract: Halide anion adsorption on transition metals can improve the performance of electrochemical CO2 reduction reaction (CO2RR), while the specific reaction mechanisms governing selective CO2RR pathways remain unclear. In this study, we demonstrate for the first time the distinct pathways for gaseous (CO) and liquid products (formate and ethanol) on the well-defined Ag-Cu nanostructures with controlled chlorination, respectively. We show that CO2 conversion to CO on Ag/AgCl can be tuned by adjusting the thickness of AgCl layer, achieving a Faradaic efficiency (FE) near 100% over a broad potential range in a 0.5 M KHCO3 using flow cell. In contrast, the optimized Cl-Ag/Cu system enables the conversion of CO2 into liquid products including formate and ethanol with a total FE nearing 100%, delivering high current density under similar conditions. In situ infrared experiments and theoretical calculations reveal that the lateral adsorbate of *OCHO intermediate facilitates the thermodynamics of both the CO pathway on Cl-Ag(111) and the formate pathway on Cl-Ag/Cu(111) by reducing Gibbs free energy barriers of each potential-limit step. This work uncovers the role of chlorination in the tuning of C-bound or O-bound intermediates during CO2RR on Ag-Cu catalysts, determining the reaction pathway under lateral adsorbate effects.

DOI: 10.1002/anie.202419456

Source: https://onlinelibrary.wiley.com/doi/10.1002/anie.202419456