Hierarchical Ti-beta obtained by simultaneous desilication and titanation as an efficient catalyst for cyclooctene epoxidation
A novel post-synthesis route to hierarchical Ti-beta zeolite and its performance as an efficient catalyst in heterogeneous cyclooctene epoxidation are presented. Catalytically active Ti sites as well as meso- and macropores are simultaneously introduced into microporous beta zeolite by hydrothermal treatment by using tetrabutyl orthotitanate as the titanation agent and tetraethylammonium hydroxide as the desilication base. Simultaneous desilication and titanation (SDT) offer the advantages of reduced experimental effort and chemical waste. The possibility to use a commercial zeolite available in high quantity as the starting material is attractive for industrialization. A significant mesopore volume (Vmeso=0.19cm3g-1) was introduced in the resulting hierarchical Ti-beta zeolite without loss of microporosity and crystallinity compared to the purely microporous counterpart. The comparison clearly demonstrates a higher catalytic activity for the hierarchical Ti-beta in cyclooctene epoxidation and accelerated desorption kinetics associated with the highly interconnected pore system.