Qiao Yan, Shen Shenyu, Mao Chenghui, Xiao Yongchun, Lai Wenchuan, Wang Yanan, Zhong Xingyu, Lu Yangfan, Li Jiong, Ge Jingjie, Hsu Hsien-Yi, Su Yaqiong, Shao Minhua, Hu Zheng, Huang Hongwen
College of Materials Science and Engineering, Hunan University, Changsha, Hunan, 410082, P. R. China.
School of Chemistry, Engineering Research Center of Energy Storage Materials and Devices of Ministry of Education, National Innovation Platform (Center) for Industry-Education Integration of Energy Storage Technology, Xi'an Jiaotong University, Xian, Shanxi, 710049, P. R. China.
Angew Chem Int Ed Engl. 2025 Mar 24;64(13):e202424248. doi: 10.1002/anie.202424248. Epub 2025 Jan 16.
Renewable electricity-driven electrochemical reduction of CO offers a promising route for the production of high-value ethanol. However, the current state of this technology is hindered by low selectivity and productivity, primarily due to a limited understanding of the atomic-level active sites involved in ethanol formation. Herein, we identify that the interfacial oxygen vacancy-neighboring Cu (O-Cu) pair sites are the active sites for CO electroreduction to ethanol. A linear correlation between the density of O-Cu pair sites and ethanol productivity is experimentally evidenced. Moreover, a high Faradaic efficiency of 48.5 % and a partial current density of 344.0 mA cm for ethanol production are achieved over the inverse CeO/Cu catalyst with a high density of O-Cu pair sites in acid. Mechanistic studies that combine density functional theory calculations and spectroscopic techniques propose an O-involved mechanism where interfacial O sites directly activate and dissociate CO into *CO in a thermodynamically spontaneous manner, thus favoring the subsequent *CHO formation and asymmetric CHO-CO coupling. Besides, the asymmetric O-Cu pair sites could preferentially stabilize the *CHCHOH intermediate, resulting in the favorable formation of ethanol over ethylene. Our findings provide new atomic-level insights into CO electroreduction to ethanol, paving the way for the rational design of future catalysts.
可再生电力驱动的二氧化碳电化学还原为生产高价值乙醇提供了一条有前景的途径。然而，目前该技术的发展受到低选择性和低生产率的阻碍，这主要是由于对乙醇形成过程中涉及的原子级活性位点了解有限。在此，我们确定界面氧空位相邻的铜（O-Cu）对位点是二氧化碳电还原为乙醇的活性位点。实验证明了O-Cu对位点密度与乙醇生产率之间的线性关系。此外，在酸性条件下，具有高密度O-Cu对位点的CeO/Cu逆催化剂上实现了48.5%的高法拉第效率和344.0 mA cm的乙醇生产分电流密度。结合密度泛函理论计算和光谱技术的机理研究提出了一种涉及氧的机理，其中界面氧位点以热力学自发的方式直接激活并将二氧化碳解离为CO，从而有利于随后的CHO形成和不对称CHO-CO偶联。此外，不对称的O-Cu对位点可以优先稳定*CHCHOH中间体，从而有利于乙醇而非乙烯的形成。我们的研究结果为二氧化碳电还原为乙醇提供了新的原子级见解，为未来催化剂的合理设计铺平了道路。
