二氧化碳(CO2)是主要的温室气体，也是重要的C1资源。采用电化学方法在温和条件下转化CO2为有用化学品近年来备受关注。其中，电化学还原CO2制备合成气是一条重要的反应路径，具有十分重要的科学意义和潜在的应用前景。本项目以探索电催化还原CO2为合成气的关键问题为目的，拟设计构建系列过渡金属硼化物(TMBs)/离子液体混合溶液的电催化体系。将实验和理论计算相结合，系统研究电催化反应活性、合成气选择性、一氧化碳和氢气的比例、电催化剂稳定性等随TMBs微观结构、元素组成、晶体结构以及电解液种类、组成等因素的变化规律。研究TMBs与电解液间匹配和协同作用机理以及离子液体与CO2分子、氢质子间相互作用机理。探索TMBs的结构特性对反应中间体在电催化剂表面吸附能力和传输速率的影响规律，阐明反应路径和机理。总结实验和理论计算结果，获得最优反应体系和反应条件，为绿色高效电催化CO2制备合成气奠定科学基础。

Carbon dioxide (CO2) is a major greenhouse gas and also an important C1 resource. Electrochemical reduction of CO2 to value-added chemicals under mild conditions has attracted much attention in recent years. Among them, electrochemical reduction of CO2 to syngas is a crucial reaction pathway, which has important scientific significance and potential application value. In this work, a series of transition-metal borides (TMBs) coupled with ionic liquids-based electrolytes will be designed to explore the major scientific issues in the process of CO2 electroreduction into syngas. By experiments and theoretical calculations, the electrocatalytic activity, syngas selectivity, the ratios of carbon monoxide and hydrogen, and the stability of electrocatalysts will be changed by the microstructures, components and crystal structures of various TMBs, and the compositions of electrolytes. The synergistic effect between TMBs and electrolytes will be discussed, and the interaction among ionic liquid, CO2, and hydrogen cation will also be investigated. A systematical research will be conducted to reveal the influence of the geometric and electronic structures of different TMBs on the adsorption energy and transport rate of intermediates on the surface of electrocatalysts. The possible reaction pathway and mechanism for electrocatalytic reduction of CO2 to syngas will be presented. Based on the results of experiments and theoretical calculations, we will find out the optimal reaction system for this reaction. This research will lay a scientific foundation for green and efficient electroreduction of CO2 to syngas.