Department of Electrical and Computer Engineering, University of Toronto, Toronto, ON M5S 1A4, Canada.
School of Chemical and Biomolecular Engineering and University of Sydney Nano Institute, University of Sydney, Sydney, NSW 2006, Australia.
Science. 2021 Jun 4;372(6546):1074-1078. doi: 10.1126/science.abg6582.
Carbon dioxide electroreduction (COR) is being actively studied as a promising route to convert carbon emissions to valuable chemicals and fuels. However, the fraction of input CO that is productively reduced has typically been very low, <2% for multicarbon products; the balance reacts with hydroxide to form carbonate in both alkaline and neutral reactors. Acidic electrolytes would overcome this limitation, but hydrogen evolution has hitherto dominated under those conditions. We report that concentrating potassium cations in the vicinity of electrochemically active sites accelerates CO activation to enable efficient COR in acid. We achieve COR on copper at pH <1 with a single-pass CO utilization of 77%, including a conversion efficiency of 50% toward multicarbon products (ethylene, ethanol, and 1-propanol) at a current density of 1.2 amperes per square centimeter and a full-cell voltage of 4.2 volts.
二氧化碳电还原（COR）作为一种将碳排放转化为有价值的化学品和燃料的有前途的途径，正在得到积极研究。然而，输入 CO 中被有效还原的部分通常非常低，对于多碳产物而言，<2%；其余的与氢氧根反应，在碱性和中性反应器中形成碳酸盐。酸性电解质可以克服这一限制，但在此条件下，析氢反应一直占据主导地位。我们报告说，在电化学活性位点附近浓缩钾阳离子可以加速 CO 的活化，从而在酸性条件下实现高效的 COR。我们在 pH<1 的条件下在铜上实现了 COR，单程 CO 利用率为 77%，在电流密度为 1.2 安培/平方厘米和全电池电压为 4.2 伏特时，多碳产物（乙烯、乙醇和 1-丙醇）的转化率为 50%。
