Effective hierarchization of TS-1 and its catalytic performance in propene epoxidation

Abstract

Abstract Hierarchical TS-1 zeolites have been synthesized by dry-gel conversion method employing conventional block copolymers F127 as scaffold. The proportion of the F127 added to the synthesis gel has a significant influence on the textural properties of the hierarchical TS-1 zeolites. Thus, by controlling the addition proportion of F127, the mesoporous pore volume and external surface area can be tailored. The functional mechanism of F127 was studied and proposed. The catalytic activity of this mesoporous TS-1 (denoted as MTS-1) was evaluated in propene epoxidation with H2 and O2. Well developed mesoporosity together with the Ti4+ atoms in tetrahedral coordination contributed to high catalytic stability than TS-1. After 120 h reaction at 200 °C, no significant decrement of catalytic activity can be observed. Moreover, the intrinsic reason for the enhanced stability is elucidated. The increased external surface and the better mass transfer ability results in the diminished coke formation and absence of heavier aromatic coke.