Synthesis And Catalytic Performance Of Zirconium Mesoporous Molecular Sieve And Mesoporous Superacid

SO42-/MxOy type solid superacid as a kind of environmentally friendly catalyst, especially SO42-/ZrO2 solid superacid has many advantages:preparation easy, thermal stability, high acid strength, noncorrosive. In the recent years, SO42-/ZrO2 solid superacid has been given extensive attention from scholars at home and abroad due to its unique advantages. But its low surface area and absorption capacity limited its application as a catalyst. This thesis mainly investigated how combination the strong acids of SO42-/ZrO2 with structure advantages of mesoporous materials to synthesis a more application prospect of mesoporous solid superacid. The major studys as follows:In the paper, Synthesis Z-x range of samples and SZ-x ranges of sample with containing SO42- by one-step method, and Synthesis ZC-x range of samples and SZC-x ranges of sample by two-step method (first pre-crystallization of ZrO2, and then mixed with the silicon source), using ZrOCl2·8H2O as zirconium source, TEOS as silica source P123 and CTAB as template. The structure of, and the surface states of these materials were determined by element analysis, UV/DRS, XRD, N2 adsorption-desorption and NH3-TPD.The results showed that:(1) The Content of zirconium in Z-x range of samples is very low(not more than 8%), When the introduction of SO42- into range of samples SZ-x range of samples, content of zirconium up to 44%. Both of Z-x samples and SZ-x samples, with Zr content increased, Ordered holes in the structure of the structure is gradually difficult, the number of holes is reduced, In higher Zr/Si, Crystal ZrO2 are all disappear. But as isolated Zr scattered in the shell of SiO2, Samples do not have the strong acid.(2) The Zr content of ZC-x samples is more than Z-x samples, when join in SO42-, The Zr content further increase. both of ZC-x samples and SZC-x samples, with Zr content increased, Ordered holes in the structure of the structure is gradually difficult, th number of holes is reduced, With the high Zr content, Zr species crystallization and the tetragonal ZrO2 disappeard, When Zr content increased, the acid of SZC-x series of samples are appeared superacid sites.(3)In the same reaction conditions, synthesis of EGEEA from 2-ethoxyethanol and acetic acid over the all sample was studied. Its the following order of catalytic activity: SZC-x samples≥ZC-x≈SZ-x≈Z-x samples, their sequence match the results of NH3-TPD. SZC-x range of samples Performance the best catalytic activity. The yield of Ethylene glycol monoethyl ether up to 80%.