The catalytic recycle and deactivation kinetics of Zn/CMK-3 catalyst for acetylene acetoxylation

Abstract

Mesoporous carbon material CMK-3 was synthesized by pyrolysis and acid washing using sucrose and SBA-15 as precursors. It served as an excellent support for the adsorption of zinc acetate in acetylene acetoxylation. The content of the oxygen-containing functional group on the surface of CMK-3 was controlled by adjusting the calcination temperature, it was found that the specific activity of Zn/CMK-3 increased with carbonyl content of CMK-3 support. Zn/CMK-3 was directly blew by C2H2 without the presence of acetic acid, vinyl acetate (VAc) was still generated even if there was no external acetic acid supply, indicating that the acetate (CH3COO−) in VAc was from the zinc acetate component. XRD, TEM, TG and XPS characterizations displayed that the catalytic recycles of acetylene acetoxylation was that zinc acetate changed to ZnO after the adsorption of C2H2, and then ZnO adsorbed the acetic acid to become zinc acetate. The deactivation kinetics of Zn/CMK-3 catalyst was proposed, catalyst deactivation was caused through one-center adsorption of feed species, and the loss of the active Zn component was the main reason for the deactivation of Zn/CMK-3 catalyst.