Abstract Ethanol dimerization to form ethyl acetate and hydrogen (EDEH) is the best atomically economic reaction and has also been considered as an environmentally friendly process in ethyl acetate synthesis. Understanding of the catalytic activities for the EDEH while preventing byproduct formation is essential to achieve the total utilization of atoms truly. We performed density functional theory calculations to investigate the EDEH on Cu in the presence of three surfaces, namely Cu(111), Cu(110), and Cu(100). The results show that the rate-limiting step of the EDEH is surface-dependent but temperature-independent at reactions lower than 800K. The rate-limiting step on Cu(110) is the CH3CHO dehydrogenation to CH3CO, whereas that of Cu(111) and Cu(100) is the ethanol dehydrogenation to CH3CH2O. In the presence of all three surfaces, the EDEH takes place mostly on both Cu(110) and Cu(100), with the rate-limiting step being the dehydrogenation of ethanol to CH3CH2O on Cu(110). We further analyzed the electronic properties of surface Cu atoms and decoupled the electronic and geometric effects. The results indicate that the electronic effect plays a critical role in the three dehydrogenation reactions, whereas the geometric effect mainly affects the C-O and H-H couplings.

中文翻译：

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多面铜催化剂上乙醇二聚制乙酸乙酯和氢气

摘要 乙醇二聚生成乙酸乙酯和氢气（EDEH）是原子经济最好的反应，也被认为是乙酸乙酯合成中的一种环保工艺。在防止副产物形成的同时了解 EDEH 的催化活性对于真正实现原子的总利用至关重要。我们进行了密度泛函理论计算，以研究存在三个表面（即 Cu(111)、Cu(110) 和 Cu(100)）时 Cu 上的 EDEH。结果表明，在低于 800K 的反应中，EDEH 的限速步骤与表面有关，但与温度无关。Cu(110) 的限速步骤是 CH3CHO 脱氢为 CH3CO，而 Cu(111) 和 Cu(100) 的限速步骤是乙醇脱氢为 CH3CH2O。在所有三个表面都存在的情况下，EDEH 主要发生在 Cu(110) 和 Cu(100) 上，限速步骤是乙醇在 Cu(110) 上脱氢为 CH3CH2O。我们进一步分析了表面铜原子的电子特性，并解耦了电子和几何效应。结果表明，电子效应在三个脱氢反应中起关键作用，而几何效应主要影响 CO 和 HH 偶联。