Experiments and kinetics of the epoxidation of allyl chloride with H2O2 over organic base treated TS-1 catalysts

Abstract

An efficacious approach to improve the catalytic performance of titanium silicalite-1 (TS-1) catalysts in epoxidation of allyl chloride with hydrogen peroxide has been developed. A series of modified TS-1 catalysts were prepared by corroding the classic TS-1 catalyst with different concentrations of tetrapropyl ammonium hydroxide (TPAOH) under controlled conditions. The resultant catalyst samples were characterized by XRD, ICP, N2-adsorption, FT-IR, UV–vis, SEM and TEM. The catalytic activity of the modified TS-1 catalysts is significantly improved, which could be attributed to the increase of the mesopore volume and pore diameter and decrease of the diffusion limitation but without obvious changes of the framework structure, framework Ti content, the outer surface shape and crystal size of the modified TS-1. Furthermore, the kinetics of the epoxidation of allyl chloride over TS-1-0.05 catalyst was also systematically studied, the apparent orders of reaction with respect to H2O2 and allyl chloride are 0.68 and 0.62, respectively, and the activation energy of the epoxidation reaction on the TS-1-0.05 catalyst is 57.4kJmol−1.