Cinnamic Acid-Assisted Synthesis of TS-1 Zeolite via π-Conjugation Regulation for Enhanced Alkene Epoxidation.

Designing high-performance TS-1 zeolites while suppressing the formation of extra-framework anatase TiO2 remains a significant challenge. In this work, cinnamic acid (CA), an aromatic acid bearing a π-conjugated side chain, was employed as a zeolite growth modifier to regulate the hydrothermal crystallization process of TS-1. Comprehensive characterization confirmed that the optimized TS-1-0.1 is free of anatase TiO2, with a substantially higher framework Ti content than conventional TS-1. Hence, TS-1-0.1 achieved a 1-hexene conversion of 32.4%, representing a 50% improvement over conventional TS-1 (21.6%). Theoretical calculations and comparative studies with hydrocinnamic acid reveal that the π-conjugated side chain of CA weakens its coordination with Ti species, facilitating the incorporation of Ti into the zeolite framework. This work establishes side-chain conjugation as a previously unrecognized structural parameter for aromatic acid-mediated zeolite crystallization, providing a molecular-level design principle for zeolite growth modifiers.