Stability and Hydrothermal Synthesis of Zirconium Incorporated MCM-41 Mesoporous Molecular Sieve

According to the initial molar ratios of ZrO2∶SiO2(0.05,0.1,0.2 and 0.3,respectively),four zirconium incorporated MCM-41 mesoporous molecular sieves(ZrMCM-41) were synthesized under hydrothermal condition using cetyl trimethyl ammonium bromide(CTAB) as a template and sodium silicate and zirconium sulfate as raw materials.The structure and morphology of the samples were characterized via various physicochemical methods such as X-ray diffraction(XRD),transmission electron microscopy(TEM),Fourier transform infrared spectroscopy(FT-IR),thermal gravimetric-differential scanning calorimeter(TG-DSC) and N2 physical adsorption.The effects of the initial molar ratio of ZrO2∶SiO2,the thermal treatment temperature and the hydrothermal treatment time on the pore structure were also investigated.Experimental results reveal that the as-synthesized samples possess a typical mesoporous structure of MCM-41 and have specific surface area in the range of 448.6—891.9 m2/g.On the other hand,with the increase in the zirconium content of the synthesized ZrMCM-41 mesoporous molecular sieve and the rise of thermal treatment temperature and the prolonging of hydrothermal treatment time,the mesoporous ordering gradually deteriorates and the Brunauer-Emmett-Teller(BET) specific surface area gradually decreases.