Isomerization of β-pinene oxide over Sn-modified zeolites

Four different Sn modified zeolites, namely three Beta zeolites with varying SiO2/Al2O3 ratio along with Sn-Y were synthesized, and characterized by XRD, TEM, SEM, pyridine adsorption desorption, nitrogen adsorption, XPS and EXAFS. Kinetics in β-pinene oxide isomerization into myrtanal was studied at 70 °C in toluene as a solvent with different catalysts. The initial isomerization rate increases with increasing acidity. Complete conversion of β-pinene oxide was achieved with the three most acidic catalysts within 30 min, whereas only 72% conversion in 1440 min was obtained with the catalyst exhibiting the lowest acidity, Sn-Beta-300. The catalyst most selective to the formation of myrtanal was Sn-Beta-300 giving 64% selectivity at 72% conversion, which is related to low amounts of acid sites.

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► Sn modified zeolites, with varying SiO2/Al2O3 ratio, were synthesized.
► Catalysts characterized by XRD, TEM, SEM, FTIR, N2 adsorption, XPS, and EXAFS.
► Kinetics of β-pinene oxide isomerization into myrtanal studied at 70 °C in toluene.
► Activity and selectivity was related to zeolite structure, type and amount of acid sites.