A DFT Study and Microkinetic Simulation in Propylene Oxidation on the “29” Cu x O/Cu(111) Surface

作者：Tian‐Tian Xiao, Rui-Shi Li, Gui‐Chang Wang · 发表于：The Journal of Physical Chemistry C · 年份：2020 · DOI：10.1021/acs.jpcc.9b11347 · 被引用次数：27 · 研究领域：Catalytic Processes in Materials Science、Catalysis and Oxidation Reactions、Mesoporous Materials and Catalysis

The propylene epoxidation reaction in a rich variety of other industrially important catalytic processes was used for synthesis of many value-added products. As an attractive and environmentally friendly process for direct epoxidation of propylene by Cu-based catalysts, the active oxidation states of Cu (Cu 0, Cu +, or Cu 0 /Cu + ) in the epoxidation reaction were widely studied. Herein, “29” Cu x O/Cu(111) was chosen to act as a precursor to bulk oxidation, as it can be observed in special oxide phases of Cu (Cu x + ). In our work, the crucial competitive reactions of dehydrogenation versus the epoxidation using the lattice oxygen (O latt *) and adsorbed molecular oxygen as the oxidants were investigated on “29” Cu x O/Cu(111) surface by virtue of the periodic density functional theory computational method. Because of the higher energy barriers of the key steps for the lattice oxygen (O latt *) as the oxidant, there are two active species in the whole reaction processes of propylene oxidation with O 2 as oxidant: the molecular O 2 * species and the atomic O* species. It was found that the molecular oxygen is difficult to dissociate on the surface directly, while the atomic O* species can be produced via the C 3 H 6 * + O latt * + OO* = C 3 H 5 * + O latt * + OOH* = C 3 H 5 O latt * + O* + OH* mechanism or by the mechanism of C 3 H 6 * + OO* = dioxametallacycle = oxametallacycle + O*. It was found that the O* mechanism is preferred for the PO formation as compared to that of ...