Mesoporous Materials Research Supported Pd, Rh Catalysts And Catalytic Properties

Recently, more and more researches and experiments have been done oncatalyst, and many catalysts have come into being, among which heterogeneouscatalyst has brought deep influence to the catalyst chemistry and the field ofchemistry around the world. The production of heterogeneous catalyst can not onlyovercome the difficulty of the cyclic utilization of catalyst, but can also overcome thedifficulty of the loss of noble metal, which help to solve the problem of the heavymetal pollution. The selection of the carrier material of heterogeneous catalyst hasgreat effect on the catalytic reaction. If you select the organosilicon material, it willnot only increase the rate of conversion, but can also save the time of reaction.Therefore, we can reach the demand of green chemistry by using water as themedium. In this article, the comparison will be made between the catalyticperformance of organosilicon material and inorganic silicon. Two kind of effectivecatalyst with different appearance will be prepared. We will also study on thecoupled reaction of Suzuki reaction and the performance of asymmetrichydrogenation of aromatic ketone.(1)The first part:we proceeded the reaction by Imidazolylsodium and(3-Iodopropyl)trimethoxysilane,producing imidazolyl ionic liquid.After Coordinatingthe imidazolyl ionic liquid and Pd(OAc)2in THF,the coordination metal complex andTEOS copolymerized in water by hydrothermal method.As finishing the all process,weobtained two catalyst of SBA-15loading Pd and PMO loading Pd as powder. Somecharacterization method can ensure the structure of these two catalyst,which is by13CNMR、29SiNMR、IR and XPS;According to BET、XRD and TEM,we can comfirmcatalyst SBA-15loading Pd and PMO loading Pd have the physical structure ofTwo-dimensional hexagonal hole.The two kind of catalyst were tested in suzukireaction.The experiment result suggest that catalysts manifest excellent activity insuzuki-coupling reaction.In addition, PMO loading Pd showed higher activity thanSBA-15loading Pd in the experiment of chloro-and bromo-aromatic compoundcoupling with phenylboronic acid.These catalyst can be reused and SBA-15loading Pd reveal no decreasing of activity after7times recycle.(2)The second part: Using CTAB/TAB and CaO as template,TEOS and1,4-Bis(triethoxysilyl)benzene were self-assembly in this atmosphere.In theprocess,function Ts-DPEN was added to be self-assembly.At last, the system eliminateCTAB/TAB by EtOH-HCl and we gain two kinds of catalyst which possess flower-likeand shell-core morphology.After the products coordinated with [Cp*RhCl2]2, catalystFlower-like loading Rh catalyst and Core-shell-structure loading Rh were obtained asorange powder.We ensure the chemical structure of these catalysts by thecharacterization of13CNMR、29SiNMR、IR and XPS. In addition, the characterizationof BET、XRD、SEM、TEM can ensure the physical struction of these catalysts.The resultof thorough research suggest that heterogeneous catalyst Rh3d orbit energy equalwith homogeneous catalyst.Some residual CTAB/TAB can not be removed byEtOH-HCl,which is detected by TG,working as phase transfer catalyst duringreaction.These catalyst were used in asymmetric hydrogen transfer of aromaticketone, which showed high activity and enantiomeric excess.(conv>99%,ee=97%).Inaddition, Flower-like loading Rh catalyst can be reused10times in the action ofasymmetric hydrogen transfer of aromatic ketone, remaining the same activity.