关键词: 介孔分子筛Ti-AlKIT-1, 钛-铝, 协同作用, 环己醇氧化

Abstract: The mixed mesoporous sieves Ti-AlKIT-1 materials were prepared through Ti grafting on AlKIT-1 obtained either directly or by post-synthesis using relatively inexpensive aluminium and titanium precursors, and characterized by FT-IR, XRD, MAS NMR, DRS, EDS and physical adsorption-desorption of nitrogen and used as catalysts toward the oxidation of cyclohexanol in 30% H2O2. XRD and N2 adsorption-desorption showed that the original mesoporous structure of the Ti-AlKIT-1 was retained with a lower BET surface area, pore volume and smaller pore size. Based on the combined FT-IR and DRS studies, it was concluded that the infrared spectroscopy can result a powerful tool to verify the Ti(Ⅳ) incorporation into the framework of AlKIT-1. 27Al MAS NMR spectra indicated that the ammonium-washed samples present only tetracoordinated aluminium. All Ti-AlKIT-1 catalysts showed significant activity in the oxidation of cyclohexanol due to the cooperative action of Ti and Al. Ti-Al(ds)KIT-1 with higher Ti/Al molar ratio and BET surface area and pore volume showed better catalytic activity than Ti-Al(ps)KIT-1. The as-prepared catalyst is stable and reusable. The conversion of cyclohexanol was 51.3％ after three runs, only decreased by 4.31% after 48 h catalytic reaction at 80 ℃.

Key words: mesoporous sieves Ti-AlKIT-1, titanium-aluminium, cooperative action, oxidation of cyclohexanol