Accelerated synthesis of TS-1 zeolite for epoxidation of 1-hexene under ambient environment: Role of sodium persulfate in inhibiting the formation of anatase species

Titanium silicalite-1 zeolite (TS-1) has been widely used as a catalyst for the epoxidation of 1-hexene. However, fast synthesis of TS-1 with high activity and stability remains a great challenge. In this study, a new strategy using sodium persulfate (SPS) as a crystallization modifier was proposed for the accelerated synthesis of anatase-free TS-1. The anatase-free TS-1 (TS-20-SPS) could be obtained after 20 h of hydrothermal crystallization. TS-20-SPS had a low Si/Ti ratio (31) and achieved a high conversion (20%) in the epoxidation of 1-hexene at room temperature (298 K), which was 200% higher than that of TS-1 synthesized without adding SPS. The addition of SPS not only accelerated the crystallization due to the generation of ·OH, but also reduced the pH value of the system to avoid the generation of anatase. This SPS-assisted approach offers an avenue for the accelerated synthesis of high-performance, anatase-free TS-1.