Carbon-encapsulated hierarchical TS-1 zeolites with enhanced hydrophobicity and catalytic epoxidation performance

Abstract

TS-1 zeolite demonstrates notable activity and selectivity in cycloolefin epoxidation when employing H₂O₂ as the oxidant. However, the practical application of conventional TS-1 is significantly limited by factors including surface hydrophilic structures and mass transfer constraints. To address these challenges, carbon-encapsulated hierarchical TS-1 (3DC_TS-1) has been synthesized through the confined growth approach, in which 3DOm carbon is used as a confined space provider for TS-1 crystallization and further acts as a hydrophobic wrapper to modulate the surface microenvironment of TS-1 crystals. In the epoxidation of cyclopentene and cyclohexene using H₂O₂ as the oxidant, the hydrophobic 3DC_TS-1 catalyst exhibits a superior selectivity to epoxide products by suppressing epoxide hydrolysis and allyl oxidation side reactions, compared with the 3D_TS-1 catalyst without the carbon wrapper and the conventionally microporous TS-1 catalyst. It is expected that the demonstrated carbon encapsulation strategy can be applied to the control synthesis of other types of zeolite catalysts.