Wang Yuxuan, Li Boyang, Xue Bin, Libretto Nicole, Xie Zhenhua, Shen Hao, Wang Canhui, Raciti David, Marinkovic Nebojsa, Zong Han, Xie Wenjun, Li Ziyuan, Zhou Guangye, Vitek Jeff, Chen Jingguang G, Miller Jeffery, Wang Guofeng, Wang Chao
Department of Chemical and Biomolecular Engineering and Ralph O'Connor Sustainable Energy Institute, Johns Hopkins University, Baltimore, MD 21218, USA.
Department of Mechanical Engineering and Materials Science, University of Pittsburgh, Pittsburgh, PA 15261, USA.
Sci Adv. 2023 Jul 28;9(30):eade3557. doi: 10.1126/sciadv.ade3557. Epub 2023 Jul 26.
Electroreduction of carbon dioxide (CO) or carbon monoxide (CO) toward C hydrocarbons such as ethylene, ethanol, acetate and propanol represents a promising approach toward carbon-negative electrosynthesis of chemicals. Fundamental understanding of the carbon─carbon (C-C) coupling mechanisms in these electrocatalytic processes is the key to the design and development of electrochemical systems at high energy and carbon conversion efficiencies. Here, we report the investigation of CO electreduction on single-atom copper (Cu) electrocatalysts. Atomically dispersed Cu is coordinated on a carbon nitride substrate to form high-density copper─nitrogen moieties. Chemisorption, electrocatalytic, and computational studies are combined to probe the catalytic mechanisms. Unlike the Langmuir-Hinshelwood mechanism known for copper metal surfaces, the confinement of CO adsorption on the single-copper-atom sites enables an Eley-Rideal type of C-C coupling between adsorbed (*CO) and gaseous [CO(g)] carbon moxide molecules. The isolated Cu sites also selectively stabilize the key reaction intermediates determining the bifurcation of reaction pathways toward different C products.
将二氧化碳（CO₂）或一氧化碳（CO）电还原为乙烯、乙醇、乙酸盐和丙醇等碳氢化合物，是实现碳负电化学合成化学品的一种有前景的方法。深入理解这些电催化过程中的碳-碳（C-C）偶联机制，是设计和开发高能量及碳转化效率电化学系统的关键。在此，我们报告了对单原子铜（Cu）电催化剂上CO₂电还原的研究。原子分散的Cu配位在氮化碳基底上，形成高密度的铜-氮基团。结合化学吸附、电催化和计算研究来探究催化机制。与铜金属表面已知的朗缪尔-欣谢尔伍德机制不同，单铜原子位点上CO₂吸附的限制使得吸附的（*CO₂）与气态[CO₂（g）]一氧化碳分子之间能够发生埃利-里德类型的C-C偶联。孤立的Cu位点还选择性地稳定了决定反应路径向不同碳产物分叉的关键反应中间体。
