Schreier Marcel, Yoon Youngmin, Jackson Megan N, Surendranath Yogesh
Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Ave., 18-163, Cambridge, MA, 02139, USA.
Angew Chem Int Ed Engl. 2018 Aug 6;57(32):10221-10225. doi: 10.1002/anie.201806051. Epub 2018 Jul 13.
The dynamics of carbon monoxide on Cu surfaces was investigated during CO reduction, providing insight into the mechanism leading to the formation of hydrogen, methane, and ethylene, the three key products in the electrochemical reduction of CO . Reaction order experiments were conducted at low temperature in an ethanol medium affording high solubility and surface-affinity for carbon monoxide. Surprisingly, the methane production rate is suppressed by increasing the pressure of CO, whereas ethylene production remains largely unaffected. The data show that CH and H production are linked through a common H intermediate and that methane is formed through reactions among adsorbed H and CO, which are in direct competition with each other for surface sites. The data exclude the participation of solution species in rate-limiting steps, highlighting the importance of increasing surface recombination rates for efficient fuel synthesis.
在一氧化碳还原过程中研究了一氧化碳在铜表面的动力学，这有助于深入了解导致氢气、甲烷和乙烯形成的机制，这三种产物是一氧化碳电化学还原中的关键产物。在乙醇介质中于低温下进行反应级数实验，乙醇对一氧化碳具有高溶解度和表面亲和力。令人惊讶的是，增加一氧化碳压力会抑制甲烷生成速率，而乙烯生成基本不受影响。数据表明，CH和H的生成通过一个共同的H中间体相连，并且甲烷是通过吸附的H与CO之间的反应形成的，它们在表面位点上相互直接竞争。数据排除了溶液物种参与限速步骤，突出了提高表面复合速率对高效燃料合成的重要性。
