Shielding effect-engineered single-crystalline Ti-rich nanosized aggregated TS-1 for 1-hexene epoxidation

Titanosilicate with H 2 O 2 stands out as a highly consequential oxidized catalytic system, prized for its user-friendly operation, mild conditions, and eco-friendly attributes. However, a synthesis strategy for large surface area titanosilicalites approaching the theoretical lowest Si/Ti ratio without extra-framework Ti species remains an ongoing challenge. In this study, we successfully synthesized single-crystalline Ti-rich nanosized aggregated TS-1 by shielding effect with a Si/Ti polymer. This polymer demonstrated effectiveness in restraining TiO 2 species by regulating the proximity of Si/Ti species in Ti-Diol-Si polymers. The polymer not only facilitated the synthesis of single-crystalline Ti-rich TS-1 but also exploited the chain length of PEG, functioning as a shielding cage by hydrogen bonds, to synthesize nanosized aggregated TS-1 (TS-1-PEG400). This TS-1-PEG400 exhibited superior conversion (~60%), selectivity (~90%), and stability in 1-hexene epoxidation. This study not only establishes a synthesis pathway for Ti-rich TS-1 but also holds the potential to enhance related industrial oxidation reactions involving titanosilicates and H 2 O 2 .