Ou Lihui, Chen Junxiang, Chen Yuandao, Jin Junling
Hunan Province Cooperative Innovation Center for the Construction & Development of Dongting Lake Ecologic Economic Zone, College of Chemistry and Materials Engineering, Hunan University of Arts and Science, Changde, 415000, China.
CAS Key Laboratory of Design and Assembly of Functional Nanostructures, Fujian Provincial Key Laboratory of Nanomaterials, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, 350002, China.
Phys Chem Chem Phys. 2019 Jul 17;21(28):15531-15540. doi: 10.1039/c9cp02394a.
An improved CO coverage-dependent electrochemical model with explicit relaxed H2O molecules used in CO2 electroreduction is presented, which is firstly applied to Cu-catalyzed CO2 electroreduction into CH4 production at low overpotentials in this paper. The results show that the present defined CH2O and CHOH pathways via common intermediates CHO and CH2 may be able to occur parallelly at the present simulated low overpotential. The potential-limiting steps may be the formation of CO and its further electroreduction into CHO, which are considered as the origin of the observed experimentally high overpotential. The present study also explains why at electrochemical interfaces, only CH4 is observed experimentally on the Cu surface rather than CH3OH. The present results are found to be in excellent agreement with the available experimental data and partial theoretical analysis, further validating the rationality of the present employed methodology.
本文提出了一种改进的、用于二氧化碳电还原的、明确考虑了松弛水分子的、与一氧化碳覆盖度相关的电化学模型，并首次将其应用于铜催化的二氧化碳在低过电位下电还原生成甲烷的过程。结果表明，目前通过常见中间体CHO和CH2定义的CH2O和CHOH途径在当前模拟的低过电位下可能能够并行发生。电位限制步骤可能是CO的形成及其进一步电还原为CHO，这被认为是实验中观察到的高过电位的根源。本研究还解释了为什么在电化学界面上，在铜表面实验中只观察到CH4而不是CH3OH。发现本研究结果与现有实验数据和部分理论分析非常吻合，进一步验证了本研究所用方法的合理性。
