DFT investigations on the conversion of acetylene to undesired vinyl acetylene during vinyl acetate synthesis

Publication date: 1 September 2017 Source:Computational and Theoretical Chemistry, Volume 1115 Author(s): Minhua Zhang, Xingyu Wu, Xuewei Huang, Bing Yang, Yingzhe Yu Density functional theory was employed to investigate the alternative mechanisms of vinyl acetylene formation on zinc acetate/activated carbon catalyst, aiming to better understand the deactivation behaviour and illustrate the plausible vinyl acetylene formation routes during vinyl acetate synthesis. The structural and energetic properties of relevant species were calculated and discussed in details. Two possible pathways for vinyl acetylene formation were proposed and they both are characterized by the generation of CHC as the rate-limiting step. It seems that CHCH prefers to undergo hydrogenation rather than dehydrogenation because of the lower barrier calculated for acetylene hydrogenation. Path2 (CHCH+H→CH2CH; CHCH→CHC+H; CH2CH+CHC→CH2CHCCH) is identified as the predominant pathway for vinyl acetylene formation on Zn(Ac)2-COOH-AC surfaces. Graphical abstract

Source: Computational and Theoretical Chemistry - July 8, 2017 Category: Chemistry Source Type: research