Effect of Oxygen-Containing Group on the Catalytic Performance of Zn/C Catalyst for Acetylene Acetoxylation

In this study, a series of activated carbon-based supports with different oxygen-containing groups (OCGs) proportions were obtained via thermal treatment in an ozone flow. Semiquantitative analyses indicated that the performance of the catalyst attained a maximum after 30 min of treatment with ozone flow, and had a positive correlation with the content ratios of carboxyl and hydroxyl groups. Further, temperature-programmed desorption analysis demonstrated that the high performance (63% acetic acid conversion) of the prepared catalyst for the acetoxylation of acetylene could be ascribed to the reduced strength of increased capacity of acetylene adsorption. Density functional theory proved that the additional -COOH in the dicarboxylic catalytic system could be employed as a support for the active sites, and enhancing C₂H₂ adsorption strength in the rate-limiting step in the actual experimental process effectively accelerated the reaction rate. Thus, the OCGs on the surface of activated carbon play a crucial role in the catalytic performance of the acetylene acetoxylation catalyst.