Enhancing the accessible TiO6 concentration and the hydrophobicity of hierarchical TS-1 zeolites for alkene epoxidation and oxidative desulfurization

The accessible TiO 6 concentration and the hydrophobicity of hierarchical TS-1 zeolites are both considered as critical factors for promoting the catalytic performance of selective oxidation. However, simultaneously enhancing these two factors still remains a challenge. Herein, hierarchical TS-1 zeolites with high hydrophobicity and concentration of accessible TiO 6 were fabricated via sequential amphiphilic organosilane-assisted pre-treatment, dry-gel conversion and hydroxyl radical post-treatment, using amphiphilic organosilane and surfactant as meso -porogens. The synthesis mechanism was investigated, and it was found that the interaction between the amphiphilic organosilane and Ti species formed during the pre-treatment benefited the formation of accessible TiO 6 during the subsequent dry-gel conversion. During the post-treatment of zeolite with H 2 O 2 solution under ultraviolet light irradiation, appropriate H 2 O 2 concentration facilitated the generation of hydroxyl radical and thus enhanced the hydrophobicity of zeolite without significantly influencing the TiO 6 concentration. The hierarchical TS-1 displayed excellent catalytic performances in 1-hexene epoxidation and oxidative desulfurization, with conversion improvements of 91.2%±2.8% and 348%±17%, respectively, compared with the conventional counterpart.