One-step Controllable Synthesis Of Hydrophobic Organic-inorganic Hybrid Zeolites And Catalytic Applications

Organic-inorganic hybrid microporous zeolites are a kind of new functional materials that combine organic groups with inorganic zeolites and have their own uniqueness and respective advantages,which expands the traditional inorganic zeolites in selective adsorption,catalysis and other fields of application.However,the application of organic-inorganic hybrid zeolites has been greatly restricted due to the limitation of difficult control.In this paper,the one-step controllable synthesis and organic catalytic application of organic-inorganic hybrid microporous zeolites were studied systematically and deeply.A series of high hydrophobic organic-inorganic hybrid zeolite materials were successfully synthesized,and it is found that they have unique and excellent catalytic performance in the fields of heterogeneous catalysis such as hydrogenation,alkaline catalysis and so on.By rotating dry-gel conversion method,the organic-inorganic hybrid zeolites were successfully synthesized in one step with Methyltriethoxysilane,Ethyltriethoxysilane,Dimethyldiethoxylsilaneas source of organic silicon and the detailed characterizations were carried out.Compared with the static dry-gel conversion method,it is found that the dynamic dry-gel conversion synthesis route not only has the advantages of green and high efficiency,but also greatly improves the utilization rate of the organic silicon source.The hybrid material synthesized with Dimethyldiethoxylsilane as organic silicon source have the optimal hydrophobicity.Its water contact angle is 150°;which is the highest in the current literature reports of hybrid zeolite materials and it shows the good hydrophobic stability.After different post-processing to the hybrid zeolites,the obtained catalysts were used in catalytic reaction of phenol hydrogenation and acid catalyzed condensation of cyclohexanone and glycol,and the excellent catalytic activity and selectivity had shown.This is a result of the hybrid materials on the reaction interface molecular interaction of effective control.By using(N,N-dimethylaminopropyl)trimethoxysilane as the source of organic silicon and comparing rotating dry gel conversion method and static dry gel conversion method,a series of N,N-dimethylaminopropyl functionalized hybrid zeolites with MOR topological structure have successfully synthesized in one step.The hybrid material shows good catalytic,activity in Knoevenagel Condensation reaction and Michael Addition reaction,which expands the application scope of hybrid zeolites.By static dry gel conversion method,using y-mercaptopropyltriethoxysilane as the source of organic silicon and adding the transition metal salts in the synthesis process,the organic-inorganic hybrid zeolites catalysts doped mercap-propyl and cobalt was synthesized in one step and the detailed characterizations were carried out.Compared with the organic-inorganic hybrid microporous zeolites catalysts in two-steps synthesis,it found that the hybrid microporous zeolites catalysts in one-step synthesis showed better catalytic activity in the reaction of catalytic air epoxidation of a-pinene.This is related to the coordination environment of cobalt in the inorganic zeolite framework and the modification of the surface properties of the materials.