Synthesis of Lewis Acid Sites in SBA-15 and Amorphous Silica Using Vapor Phase Infiltration of Zr and Sn.

Vapor-phase infiltration of organometallic or inorganic compounds was used to synthesize Lewis-acid sites in both amorphous SiO2 and mesoporous SBA-15. Isolated Zr and Sn sites produced in this manner exhibited similar reaction and adsorption properties as that observed for Zr-BEA and Sn-BEA zeolites. Adsorbed CD3CN showed a characteristic ν(C≡N) stretch at 2300 cm−1 which was not observed on bulk ZrO2 or siliceous materials. Zr- and Sn-modified SiO2 and SBA-15 also showed similar activities to Zr-BEA and Sn-BEA for transfer hydrogenation/etherification of 5-hydroxymethylfurfural with 2-propanol and the Diels–Alder cycloaddition/dehydration of 2,5-dimethylfuran with ethene. [ABSTRACT FROM AUTHOR]