Synthesis And Catalytic Performance Of Hierarchically Porous Metal Oxides

Hierarchically porous materials are multi-scale porous structure materials.Compared with traditional porous materials,hierarchically porous materials possess abundant pore structure,large pore volume and high specific surface area,which have been widely used in adsorption,energy catalysis and other fields.However,the assembly methods of hard and soft templates are uncontrollable in the synthesis process,and it is very difficult to control the ordered structure and the size of all levels of macroporous-mesoporous materials at the same time.Therefore,it is hard to obtain macroporous-mesoporous materials with ordered structure and adjustable pore size.In order to achieve one-step assembly of macroporous-mesoporous structures and ordered pore structure at all levels,great efforts have been devoted.Meanwhile,the macroporous-mesoporous materials have shown good application prospects in catalysis due to their multi-scale pore structure,high specific surface area and interoperable pore structure.Hence,the preparation of macroporous-mesoporous materials with uniform and ordered porous structure and their use as catalysts for larger molecular sizes have become a research hotspot.In this thesis,the co-assembly of double template was used to realize the simultaneous assembly of macroporous template and mesoporous template.The macroporous-mesoporous Ti O₂ with highly ordered macroporous structure and mesoporous structure was synthesized.Moreover,the microporous diameter can be controlled by adjusting the size of macroporous template.The prepared macroporous-mesoporous Ti O₂ was used as a catalyst for the click reaction for thiol and olefin,which exhibited excellent photocatalytic performance.At the same time,the mesoporous structure of macroporous-mesoporous Ti O₂ could effectively limit the growth of polymer,and successfully synthesize the polymer with a molecular weight concentration,which effectively solves the problem of large and unconcentrated molecular weight in the polymer field.Highly ordered mesoporous ZrO₂ materials were prepared by solvent volatilization induced self-assembly.By controlling the volatilization temperature of the solvent,the morphology of ordered mesoporous ZrO₂ materials was controlled,and the ordered mesoporous ZrO₂ with spheres and nanorod arrays was obtained.The 10%Ni was supported on the mesoporous ZrO₂ microspheres and nanorod arrays by impregnation method,which were used as catalysts for the selective hydrogenation of stearic acid,exhibiting high catalytic activity and selectivity.The reaction conversion is up to84.3%,and the selectivity of the target product is 23.1%.