Abstract: As CO₂ is a vital reagent for the production of useful chemicals,it is high time to find an efficient way to make use of it. The electrochemical reduction of CO₂,which can be conducted under the ambient conditions and converse CO₂ into various products,provides a promising future both for the utilization of CO₂ and for the human beings. The products,the reaction rate and the selectivity of the reaction can be adjusted by conducting the reaction on different electrodes and at different over potentials. This paper highlights the progress of the electrochemical reduction of CO₂ in aqueous electrolyte and summarizes the mechanism of electrochemical reduction of CO₂ proposed by various workers and introduces the main reactions occurred during the reduction process. Studies carried out on different kinds of electrodes,such as metal electrodes,gas diffusion electrodes (GDEs) and composite electrodes and so on,have also been reviewed. The products,the selectivity of the reaction and the currency during the process of reduction,also vary with the materials of the electrodes. Besides,the reaction conditions,such as the pressure and the temperature,also affect the reaction rate and the currency. Finally,the applicative prospects of the technology of the electrochemical reduction of CO₂ are proposed and the aqueous electrolytes can provide profuse [H] and then there will be more CO₂ molecules reduced into fuel molecules,which is of great value both in environmental protection and resource utilization and economic development.

Key words: carbon dioxide, electrochemistry, reduction, electrodes

摘要： CO₂作为一种潜在的碳资源,寻找一种有效的方法转移利用CO₂一直是社会关注的焦点。水溶液中电化学方法转化固定CO₂可在室温和常压下进行,通过选择不同电极和电极电势来改变产物、调控反应速率和选择性,因而具有潜在的优势。本文综述了水溶液中电化学还原CO₂的发展现状,介绍了水溶液中电还原CO₂的基本原理和电极上发生的主要反应;总结了水溶液中金属电极、气体扩散电极(GDEs)和复合电极等不同电极材料对CO₂还原产物的种类、选择性以及电流效率的影响;讨论了温度、CO₂分压等还原反应条件对反应速率和电流效率的影响。展望了水溶液中电还原CO₂技术的发展前景,认为利用水基溶液中丰富的[H],增强CO₂还原产物的燃料化程度,将在环境保护、资源利用和经济效益方面具有极大价值,符合绿色化学发展理念。

关键词: 二氧化碳, 电化学, 还原, 电极材料