Cu(I) Reducibility Controls Ethylene vs Ethanol Selectivity on (100)-Textured Copper during Pulsed CO 2 Reduction
Cu(I) Reducibility Controls Ethylene vs Ethanol Selectivity on (100)-Textured Copper during Pulsed CO 2 Reduction
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Cu(I) 还原性控制脉冲 CO 2 还原过程中 (100) 织构铜上乙烯与乙醇的选择性
DOI：
10.1021/acsami.0c17668
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发表时间：
2021
影响因子：
9.5
通讯作者：
Suntivich, Jin
中科院分区：
文献类型：
--
作者：
Tang, Zhichu;Nishiwaki, Emily;Fritz, Kevin E.;Hanrath, Tobias;Suntivich, Jin
电化学CO2还原反应（CO2 RR）可以将广泛存在的CO2转化为具有附加值的C2产品，如乙烯和乙醇。然而，对任一化合物的低选择性限制了当前CO2 RR电催化剂的有效性。在此，我们报道了在（100）织构多晶铜箔上使用脉冲过电位将乙烯选择性提高到67%，总C2选择性>75%。通过控制反应温度，可以使脉冲CO2 RR对乙烯或乙醇具有选择性。我们归因于增强的C2选择性的改善CO二聚动力学的活性Cu表面上的主要（100）-织构的Cu晶粒与减少的氢吸附覆盖率在脉冲CO2 RR。乙烯对乙醇的选择性可以通过在阴极电位循环期间Cu（I）物种的还原来解释。我们的工作证明了一个简单的路线，以提高乙烯与乙醇的选择性，并确定Cu（I）的物种负责乙醇的生产。
The electrochemical CO2reduction reaction (CO2RR) can convert widely available CO2into value-added C2products, such as ethylene and ethanol. However, low selectivity toward either compound limits the effectiveness of current CO2RR electrocatalysts. Here, we report the use of pulsed overpotentials to improve the ethylene selectivity to 67% with >75% overall C2selectivity on (100)-textured polycrystalline Cu foil. The pulsed CO2RR can be made selective to either ethylene or ethanol by controlling the reaction temperature. We attribute the enhanced C2selectivity to the improved CO dimerization kinetics on the active Cu surface on predominately (100)-textured Cu grains with the reduced hydrogen adsorption coverage during the pulsed CO2RR. The ethylene vs ethanol selectivity can be explained by the reducibility of the Cu(I) species during the cathodic potential cycle. Our work demonstrates a simple route to improve the ethylene vs ethanol selectivity and identifies Cu(I) as the species responsible for ethanol production.