文献类型：会议论文

英文题名：Reaction mechanism of methyl nitrite dissociation during co catalytic coupling to dimethyl oxalate: A density functional theory study

作者：Fan, Chen[1];Luo, Man[2];Xiao, Wende[2]

机构：[1]E China Univ Sci & Technol, Minist Educ, Key Lab Adv Control & Optimizat Chem Proc, Shanghai 200237, Peoples R China;[2]Shanghai Jiao Tong Univ, Sch Chem & Chem Engn, Shanghai 200240, Peoples R China

会议论文集：6th Global Chinese Symposium of Chemical Engineering

会议日期：JUL 16-19, 2014

会议地点：Pokfulam, PEOPLES R CHINA

语种：英文

外文关键词：Methyl nitrite; Catalytic; Non-catalytic; Dissociation; Density functional theory

摘要：Dissociation of methyl nitrite is the first step during CO catalytic coupling to dimethyl oxalate followed by hydrogenation to ethyl glycol in a typical coal to liquid process. In this work, the first-principle calculations based on density functional theory were performed to explore the reaction mechanism for the non-catalytic dissociation of methyl nitrite in the gas phase and the catalytic dissociation of methyl nitrite on Pd(111) surface since palladium supported on alpha-alumina is the most effective catalyst for the coupling. For the non-catalytic case, the calculated results show that the CH3O-NO bond will break with a bond energy of 1.91 eV, and the produced CH3O radicals easily decompose to formaldehyde, while the further dissociation of formaldehyde in the gas phase is difficult due to the strong C-H bond. On the other hand, the catalytic dissociation of methyl nitrite on Pd(111) to the adsorbed CH3O and NO takes place with a small energy barrier of 0.03 eV. The calculated activation energies along the proposed reaction pathways indicate that (i) at low coverage, a successive dehydrogenation of the adsorbed CH3O to CO and H is favored while (ii) at high coverage, hydrogenation of CH3O to methanol and carbonylation of CH3O to methyl formate are more preferred. On the basis of the proposed reaction mechanism, two meaningful ways are proposed to suppress the dissociation of methyl nitrate during the CO catalytic coupling to dimethyl oxalate. (C) 2015 The Chemical Industry and Engineering Society of China, and Chemical Industry Press. All rights reserved.