Renewable Zn/S-1 catalyst with dual active sites for acetylene acetoxylation

Abstract

The prevailing Zn/AC catalysts was plagued by limited lifetime and difficulties in regeneration for acetylene acetoxylation. In order to exploring renewable catalyst for acetylene acetoxylation, Zn/S-1 catalyst was synthesized using Silicalite-1(S-1) as support. The catalytic performance of Zn/S-1 was compared with Zn/AC catalyst using active carbon as support. The CH₃COOH conversion of Zn/S-1 catalyst only decreased 15 % after running 225 h, much better than the 66 % of Zn/AC after 154 h. TG analysis revealed that the improved stability of Zn/S-1 catalyst was attributed to its better resistance for carbon deposition with the presence of S-1 support. A series of characterizations and DFT results elucidated that the Lewis acid sites of S-1 support and Zn component serve as dual active sites, which enhanced the adsorption of CH₃COOH and inhibited the carbon deposition. In addition, the deactivated Zn/S-1 catalyst could be regenerated by calcination in air atmosphere due to the thermal stability of S-1, and the regenerated Zn/S-1 catalyst showed similar catalytic activity with the fresh catalyst.