近日，中国电子科技大学崔春华团队报道了体相水氧化还原化学实现CO2电还原中的自由基介导的C-C偶联。2025年9月22日出版的《自然-化学》杂志发表了这项成果。

长期以来，电催化一直被视为一种界面过程，因此体相水氧化还原化学的作用在很大程度上仍未被探索。

研究组证明了电解质诱导的水氧化还原自由基激活体溶液中的反应物在带电界面进行电催化。以甲酸盐为模型电解质，通过电子顺磁共振、高分辨率质谱和拉曼光谱分析发现，水中氢键断裂产生氧化还原自由基，甲酸盐氧化生成C1中间体。甲酸盐浓度依赖的氢键重组驱动了水基自由基和活性中间体的连续生成，使体相水成为一种活性氧化还原介质，而不是被动溶剂。原位电化学研究表明，这些C1中间体迁移到Cu阴极表面，通过自由基介导的途径实现C-C偶联。这项工作挑战了电催化仅仅是一个界面过程的传统观点，并通过定制电解质工程为高效的电化学合成提供了另一种设计原则。

附：英文原文

Title: Bulk water redox chemistry enables radical-mediated C–C coupling in CO2 electroreduction

Author: Li, Lei, Cui, Chunhua

Issue&Volume: 2025-09-22

Abstract: Electrocatalysis has long been viewed as an interfacial process, so the role of bulk water redox chemistry remains largely unexplored. Here we demonstrate that electrolyte-induced water redox radicals activate reactants in bulk solution for electrocatalysis at electrified interfaces. Using formate as a model electrolyte, we show that hydrogen-bond disruption in bulk water generates redox radicals, which oxidize formate to generate C1 intermediates, as revealed by electron paramagnetic resonance, high-resolution mass spectrometry and Raman spectroscopy. Formate concentration-dependent hydrogen-bond restructuring drives the sequential generation of water-derived radicals and reactive intermediates, establishing bulk water as an active redox mediator rather than a passive solvent. In situ electrochemical studies demonstrate that these C1 intermediates migrate to the Cu cathode surface, enabling C–C coupling via radical-mediated pathways. This work challenges the conventional view of electrocatalysis as solely an interfacial process and offers an alternative design principle for efficient electrochemical synthesis through tailored electrolyte engineering.

DOI: 10.1038/s41557-025-01948-z

Source: https://www.nature.com/articles/s41557-025-01948-z