Hierarchical Beta Zeolites As Catalysts in α-Pinene Oxide Isomerization
Roman Barakov, Nataliya Shcherban, Päivi Mäki‐Arvela, Pavel S. Yaremov, Igor Bezverkhyy, Johan Wärnå, Dmitry Yu. Murzin
Abstract
High Resolution Image Download MS PowerPoint Slide Hierarchical beta zeolites obtained in the concentrated reaction mixtures (H 2 O/Si = 2.5) and micromesoporous materials synthesized using a dual-template approach from a zeolite beta precursor were rigorously characterized and tested in a sustainable and environmentally friendly process of α-pinene oxide isomerization. The highest yield of trans -carveol (42%) with chemopreventive activity of mammary carcinogenesis was achieved over low crystalline micromesoporous materials characterized by well-developed mesoporosity, an increased fraction of weak-to-medium Brønsted acid sites and low Brønsted and Lewis acid sites (BAS/LAS) ratio. In turn, highly crystalline hierarchical beta zeolites with a lower mesopore volume and the mesopore surface area, stronger Brønsted acidity, and a higher BAS/LAS ratio favored the formation of campholenic aldehyde (31% yield). The mechanism of the desired product and byproducts formation was discussed and its feasibility was confirmed by kinetic modeling.