Synthesis And Catalysis Of Mesoporous Functional Composite

Porous material has played a role that could not be ignored in the development of the human society since it appeared. At the present time, zeolite molecular sieves hold the station with no substitute in the catalytic materials, adsorption and separation materials, and ions-exchange materials et al. In 1992, Mobil corp. initiated the mesoporous material—M41S family, and opened a new page on the development of porous materials. Compared with the traditional zeolites, the hydrothermal stability and thermal stability of the mesoporous materials are weaker, but the mesoporous materials have uniform adjustable pore, high surface area, well-ordered in macro scale. These characters lay a good foundation for the application of mesoporous materials. The researches of the application are spreading like a raging fire.SBA-15 is another kind of well-known mesoporous materials, and is synthesized in the acidic media with triblock copolymer P123 as the template. Comparing with MCM-41, SBA-15 has bigger pore, thicker pore wall, higher hydrothermal stability. More important, it provides a large number of active sites on the surface of SBA-15. It makes sense to anchor organic functional groups on the surface. It can also introduce organic functional groups directly in the hydrothermal synthesis of mesoporous materials, although it reduces the mesopore ordering, it is an easy and efficient method to synthesis organic functional mesoporous materials. We have prepared mesoporous material with catalysis functional groups and investigated the catalytic activity.First of all, organic functional groups ethylenediamine were successfully anchored on the surface of SBA-15. Then we introduced HAuCl4 and reduced by NaBH4, finally we got the functionalized material SBA-15 with nano Au clusters in the pores. XRD and N2 adsorption-desorption showed that the material remained two-dimentional hexagonal pore structure and large surface area; TEM showed that the nano Au clusters dispersed in the pores of SBA-15. We investigated the oxygen catalytic activity. In comparison with toluene, the acetonitrile solvent gives higher yields in the same reaction conditions. Using actonitrile as the solvent and oxygen as oxidant, under 80℃, the material showed higher catalytic performance with 1-phenethylacohol and p-chloro-1-phenethylacohol. It gave as high as 80% isolated yields.Using CTAB and DM-3010 mixed micelle, we prepared a series of mesoporous materials containing secondary and quaternary ammonium by co-condensation hydrothermal synthesis. XRD and N2 adorption-desorption showed that these materials had similar pore structures as MCM-41; SEM showed they were nano balls of 100nm. We investigated the catalytic activity of the preparation of styrene cyclic carbonate by the couple of CO2 with styrene oxide. With no solvent and the reaction conditions of 120℃7MPa 6h, when secondary and quaternary ammonium exited separately, the selectivity of styrene cyclic carbonate was improved, and when secondary and quaternary ammonium worked together, both the conversion of styrene oxide and the selectivity of styrene cyclic carbonate were increased greatly. The conversion of styrene oxide could reach 54% and the selectivity of styrene cyclic carbonate 92%.