Chaoyue Zhao, Xianming Zhang, Ziting He, Qingxin Guan* and Wei Li*, Inorg. Chem. Front., 2020, DOI: 10.1039/D0QI00694G For
acetylene hydrochlorination, as a substitute for toxic mercury catalysts,
Cu-based catalysts are probably the most promising and highly active non-noble
metal catalysts. Here, density functional theory (DFT) was used to reveal the
mechanism how NMP ligand significantly promotes the activity and stability of
Cu-catalyzed acetylene hydrochlorination reaction. According to the
experimental and DFT results, the high activity of the NMP coordinated Cu-based
catalyst is attributed to the interactions of catalyst−ligand and
substrate−ligand, which stabilize the substrate−Cu(II)−ligand complex in the
catalytic cycle. Moreover, the most important two stages were investigated in
detail: the reduction of (i) Cuα+ to Cu0 and (ii) Cu2+ to Cu+ during the reaction process. The results demonstrate that the
NMP ligand prevents high valence Cu2+ being reduced due to the
geometric distortion influence and hydrogen bond interaction between the
catalysts and ligands. Also, NMP could inhibit the carbon deposition by
avoiding the formation of Cu(0) and its strong adsorption of acetylene on the
surface.
