| In this thesis, a summary of the evolution of the solid acid catalysts is first made and cast a light on the problems and limitations of such catalysts used in the alkylation's reaction. Taking the alkylation's character into account, we put forward a possible measurement. Then on the basic fact that porous materials possess outstanding property as catalyst supporter, a discussion of the non-silica mesoporous metal oxides on the synthesis strategies, routes, mechanism, et al is made. Consequently, a feasibility to prepared novel compound mesoporous solid strong acid is pointed outIn the second and third part of this thesis, zirconia is selected as supporter and poly-template method is exploited to prepared mesostructured material doped active components Mo and W, then solid strong acid catalyst, MoO3/ZrO2 and WO3/ZrO2, are obtained. Many kind of techniques including XRD, BET, TEM,FI-IR,NH3-TPD and NMR are used to characterize the samples' structure and acid. It is found that1. A series of meosporous MoO3/ZsO2. calcined at different temperature using polyvinyl alcohol as template have been prepared. By x-ray-diffraction, it was found that MoO3 is beneficial to promote the crystallization of zirconia pore walls and hinder the transformation from meta-tetragonal phase to stable monoclinic phase. Zirconia existed predominantly in the phrase of tetragon even when the calculation temperature is up to 800℃. The nitrogen adsorption-desorption isotherms were found to be of type IV and the hystersis loop in the desorption branch obviously show the existence of mesopores. The mesopore size distribution calculated from the desorption branch by the BJH method is very narrow, with average pore width value of 3-4nm. A large quantity of 'worm-like' mesopores is detected by TEM.2. Formation mechanism of mesoporous MoO3/ZrO2 is roughly put forward, which differentiates from M41S materials. In our case, the mesostructure is probably resulted from hydrogen-bonding direction of inorganic-template interaction. In comparison with that of static, it is weaker which leads to a porous structure lack of long-rang ordering.3. Through FI-IR, it is found that the present of Mo-O-Zr is probably the new strong acidity center. NH3-TPD shows that MoO3/ZrO2 processes several acid sites with higher acidity scale and enhancing the MoO3 loading on zirconia within its limiting value will increase the acid concentration and acidity scale.4. By high solution NMR, combining MAS(Magic Angle Spinning), CP (cross-polarization) techniques, and many kind of base probing molecular, a fine surface acidity characterization of meosporous MoO/ZrC is made. H MAS NMR shows that there are several kind acidity sites, which confirms the result of NH-TPD; on the surface of synthesized samples, 31P CP/MAS NMR detects strong Bronsted acid sites, whereas no Lewis acid sites are present. 13C CP/MAS NMR shows that such solid acid possesses relatively high acidity scale, whose chemical shift is 226ppm, stronger than that of molecular sieve HZSM-5.5. A comparison between mesoporous MoO3/ZrO2 and mesoporous WO3/ZrO2 on surface acidity is also made by NMR, which shows that mesoporous WO3/ZrO2 presents the acidity property analogous to that of mesoporous MoO3/ZrO26. Combining the observed results of FI-IR and NMR, the acidity model of mesoporous MoO3/ZrO2 with three kind of structure is first put forward."In the last part, a summary of the work in this thesis is made, and the vista of the future work we will continue is pointed out.The result of this thesis is a attempt of preparing novel solid acid catalysts, extending the applying scope of the non-silica mesoporous materials. Also it fulfills the the green chemistry and environmentally friendly goal, which exert a positive role on the design and practical application of solid acid catalysts for alleyiation's reaction. |
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