中国科学院化学研究所韩布兴团队报道了聚乙二醇调节电极表面微环境增强CO₂电还原多碳产物。相关研究成果发表在2025年1月8日出版的国际学术期刊《德国应用化学》。

调节电极的表面微环境是提高CO₂电还原电催化性能的关键。

该文中，研究人员提出了一种创新方法，在制备CuPEG电极的过程中，将少量线性低聚物聚乙二醇（PEG）掺入Cu₂O催化剂中。在流动池中，在1 M KOH的500 mA cm^-2下，对多碳产物（C2+）的法拉第效率（FE）从没有PEG的Cu电极上的69.3%增加到CuPEG电极上的90.3%。

原位研究和理论计算表明，PEG分子通过氢键相互作用显著改变了铜表面的微环境。这种修饰导致Nafion的弛豫，增加了活性位点的可用性，增强了*CO和*OH的吸附，从而促进了C-C偶联。同时，重建的氢键网络减少了活性氢物种的存在，从而抑制了析氢反应。

附：英文原文

Title: Enhancing CO2 Electroreduction to Multicarbon Products by Modulating the Surface Microenvironment of Electrode with Polyethylene Glycol

Author: Yiyong Wang, Yingying Cheng, Shiqiang Liu, Yaoyu Yin, Jiahao Yang, Hengan Wang, Ke Li, Meng Zhou, Jiapeng Jiao, Pei Zhang, Qingli Qian, Qinggong Zhu, Xiaofu Sun, Yi Xu, Xinchen Kang, Mingchuan Luo, Buxing Han

Issue&Volume: 2025-01-08

Abstract: Modulating the surface microenvironment of electrodes stands as a pivotal aspect in enhancing the electrocatalytic performance for CO2 electroreduction. Herein, we propose an innovative approach by incorporating a small amount of linear oligomer, polyethylene glycol (PEG), into Cu2O catalysts during the preparation of the CuPEG electrode. The Faradaic efficiency (FE) toward multicarbon products (C2+) increases from 69.3% over Cu electrode without PEG to 90.3% over CuPEG electrode at 500 mA cm2 in 1 M KOH in a flow cell. In situ investigations and theoretical calculations reveal that PEG molecules significantly modify the microenvironment on the Cu surface through hydrogen bond interactions. This modification leads to the relaxation of Nafion, increasing the availability of active sites and enhancing the adsorption of *CO and *OH, which in turn promotes C–C coupling. Concurrently, the reconstructed hydrogen bond network reduces the presence of active hydrogen species, thereby inhibiting the hydrogen evolution reaction.

DOI: 10.1002/anie.202420661

Source: https://onlinelibrary.wiley.com/doi/10.1002/anie.202420661