Liquid–Solid Mixture Seed-Assisted Synthesis of Hierarchical TS-1 Zeolite for Efficient Oxidative Desulfurization

Abstract

The addition of an additional mesoporous/macroporous templating agent inevitably has an adverse effect on the economy and greenness of the seed-assisted synthesis process for hierarchical zeolites; hence, the development of an efficient seed-assisted method for the synthesis of hierarchical zeolite without the addition of an additional additive is appealing. Herein, we reported the preparation of hierarchical TS-1 zeolite with a large amount of mesopores using a liquid–solid mixture seed-assisted method and its application as a heterogeneous catalyst in the oxidative desulfurization reactions. The characterization results disclosed that the liquid–solid mixture seed was more conducive to the formation of hierarchical TS-1 zeolite than liquid seed alone and solid seed alone. The formation process of hierarchical TS-1 zeolite with different crystallization times was investigated in detail, and accordingly, a possible two-stage crystallization mechanism was proposed. In addition, the synthesized hierarchical TS-1 zeolite showed remarkably enhanced catalytic activity in the oxidative desulfurization of dibenzothiophene (DBT) and 4,6-dimethyldibenzothiophene (4,6-DMDBT) in comparison to the conventional microporous TS-1 zeolite. This work provides some guidance for the development of a more efficient and greener seed-assisted synthesis method for hierarchical zeolites without the addition of any additional mesoporous/macroporous templating agent.