Isomerization of alpha-pinene oxide over ZSM-5 based micro-mesoporous materials

Few types of ZSM-5 based micro-mesoporous materials obtained via a dual template method, steam-assisted conversion and dual-functional templating were evaluated in a-pinene oxide isomerization. Complete conversion and the highest selectivity towards trans-carveol (ca. 40-43%) were achieved over X-ray amorphous micro mesoporous aluminosilicates as well as mesoporous molecular sieves AlSi-SBA-15. In addition, X-ray amorphous samples containing the secondary building units of ZSM-5 zeolite demonstrated the highest rate of alpha-pinene oxide isomerization. The yield of the most desired product trans-carveol to a large extent depends on the accessibility of acid sites to the reagents molecules and acidity of the catalysts (strength and concentration of Bronsted and Lewis acid sites).