Ou Lihui, He Zixi, Yang Hai, Chen Yuandao
Hunan Province Cooperative Innovation Center for the Construction & Development of Dongting Lake Ecologic Economic Zone, Hunan Provincial Key Laboratory of Water Treatment Functional Materials, Hunan Province Engineering Research Center of Electroplating Wastewater Reuse Technology, College of Chemistry and Materials Engineering, Hunan University of Arts and Science, Changde 415000, China.
Hunan Provincial Key Laboratory of Environmental Catalysis & Waste Recycling, Hunan Institute of Engineering, Xiangtan 411104, PR China.
ACS Omega. 2021 Jul 6;6(28):17839-17847. doi: 10.1021/acsomega.1c01062. eCollection 2021 Jul 20.
An improved CO coverage-dependent electrochemical interface model with an explicit solvent effect on Cu(100) is presented in this paper, by which theoretical insights into the potential-dependent C-C bond formation pathways occurring in CO electrochemical reduction to C products can be obtained. Our present studies indicate that CHO is a crucial intermediate toward C products on Cu(111), and dimer OCCO is found to not be a viable species for the production of C products on Cu(100). The reaction pathway of CHO with CO and CHO dimerization into dimers COCHO and CHOCHO may be C-C bond formation mechanisms at low overpotential. However, at medium overpotential, C-C bond coupling takes place preferentially through the reaction of COH with CO species and COH dimerization into dimers COCOH and COHCOH. The formed dimers COCHO, CHOCOH, and CHOCHO reactions of CHO with CO, COH, and CHO species may lead to C products, which are regarded as C-C bond formation mechanisms at high overpotential. The difference of obtained adsorption isotherms of CO on Cu(100) with that of Cu(111) may be able to explain the effect of the crystal face of Cu on product selectivity. The excellent consistencies between our present obtained conclusions and the available experimental reports and partial theoretical studies validate the reasonability of the present employed methodology, which can be also used to systematically study potential-dependent CO electroreduction pathways toward C products on Cu(100) or other metal catalysts.
本文提出了一种改进的、明确考虑溶剂对Cu(100)影响的CO覆盖度依赖型电化学界面模型，通过该模型可获得对CO电化学还原为C产物过程中电位依赖型C-C键形成途径的理论见解。我们目前的研究表明，CHO是Cu(111)上生成C产物的关键中间体，并且发现二聚体OCCO不是Cu(100)上生成C产物的可行物种。在低过电位下，CHO与CO反应以及CHO二聚形成二聚体COCHO和CHOCHO的反应途径可能是C-C键形成机制。然而，在中等过电位下，C-C键耦合优先通过COH与CO物种反应以及COH二聚形成二聚体COCOH和COHCOH发生。形成的二聚体COCHO、CHOCOH和CHOCHO与CHO、CO、COH物种的反应可能导致生成C产物，这些被视为高过电位下的C-C键形成机制。CO在Cu(100)上获得的吸附等温线与在Cu(111)上的差异可能能够解释Cu晶面对产物选择性的影响。我们目前得出的结论与现有实验报告和部分理论研究之间的出色一致性验证了所采用方法的合理性，该方法也可用于系统研究Cu(100)或其他金属催化剂上电位依赖型CO电还原为C产物的途径。
