Surface Science | 2021
Ethanol dimerization to Ethyl acetate and hydrogen on the multifaceted copper catalysts
Abstract
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.