MCl2 (M=Hg, Cd, Zn, Mn) catalysed hydrochlorination of acetylene - a Density Functional Theory study

摘要

A Density Functional Theory method has been employed in this research to conduct an in-depth study of the correlation between the conversion of acetylene to vinyl chloride catalysed by MCl2 (M=Hg, Cd, Zn, Mn) and the electron affinity. From the analysis of the adsorption energy and energy profile of acetylene hydrochlorination reaction, combined with Fukui indices and outer-shell Mulliken population change alongside reaction pathway, it can be concluded that, the outermost electron migration is the main factor affecting the catalytic property of MCl2 (M=Hg, Cd, Zn, Mn) catalyst. The Mulliken population change of the central atom M2+ (M=Hg, Cd, Zn) share similar tendency along the reaction pathway, the only difference is Hg2+ gained more electrons than the other two when acetylene got absorbed, and that proved that Hg(II) got better electron withdrawing, which is a main motivator of better catalytic properties in acetylene hydrochlorination reaction.