Preparation And Catalytic Property Of ZrO₂Macroporous Inorganic Composite Materials

In this paper, on the basis of previous researchers work about SiO₂macroporous material, weprepared two macroporous materials with3D connected interpenetrating large channel, i.e.ZrO₂and TiO₂, via a3D skeletal polymer as template through surface replica technique. By usingthis type of macroporous materials as supports, whose structure played guiding role in the surfacechemical modification, we obtained three composite solid acid materials, i.e. SO₄^2-/ZrO₂-SiO₂,SO₄^2-/ZrO₂-TiO₂, WO₃/ZrO₂and a composite solid base MgO/ZrO₂.Studies the catalyticperformance of these composite catalytic materials containing ZrO₂in liquid phase reaction.Theresearches of this article are as follows:Firstly, macroporous ZrO₂and TiO₂materials were prepared respectively by using a three-dimensional （3D） epoxy resin based skeletal polymer through an in situ hydrolysis of the precursorsolution, i.e. Zirconium butoxide, Tetrabutyl titanate, and a subsequent calcination at hightemperature. These materials accurately reproduced the surface morphology of porous polymer andformed micron grade3D connected interpenetrating large channel,which has the very strongcapillary effect, can prevent the substances reunion and association in the pore.The structure ofguiding role in the surface chemical modification has obvious advantages.Secondly, macroporous SiO₂, TiO₂and ZrO₂materials were easy to functional, by using thischaracteristic, we carried out the in situ preparation of nanostructured functional materials researchand prepared three macroporous ZrO₂solid acid composite materials, whose structure has effect oncatalytic activity.SO₄^2-/ZrO₂-SiO₂solid superacid: A macroporous ZrO₂/SiO₂composite was prepared by usinga macroporous SiO₂as a support and introduction of ZrO₂via the dipping-hydrolysis method.SO₄^2-/ZrO₂-SiO₂material was prepared by immersing ZrO₂/SiO₂in H2SO4solution, indicating asolid superacid catalyst. With the synthesis of butyl acetate as the probe reaction and study thepreparation conditions on the influence of catalytic activity.The results show that the SO₄^2-/ZrO₂-SiO₂catalyst exhibits a better activity of esterification and the better yield of n-butyl acetate （97%）is obtained when the concentration of H2SO4is1.5mol·L-1and the calcination temperature is550℃. SO₄^2-/ZrO₂-TiO₂solid superacid: A macroporous TiO₂support was prepared by using3Dskeletal polymer through an in situ hydrolysis of Butyl titanate and a subsequent calcination at hightemperature. SO₄^2-/ZrO₂-TiO₂solid superacid catalyst was prepared by using the macroporous TiO₂as a support and introduction of ZrO₂via the dipping-hydrolysis method.The results show that theSO₄^2-/ZrO₂-TiO₂catalyst exhibits a better activity of esterification and the better yield of n-butylacetate （91.4%） is obtained when the content of ZrO₂is35wt%,the concentration of H2SO4is2.0mol·L-1and the calcination temperature is700℃.WO₃/ZrO₂solid acid: By impregnation, calcination of ammonium tungstate solution, whichused3D zirconia layer as support, we prepared WO₃/ZrO₂macroporous composite materials.WO₃functional nanomaterials could be in situ synthesized and shaped as a3D continuous filmcovering the zirconia layer. By using the esterification of methyl oleate from oleic acid andmethanol as the probe reaction, we found that when the calcination temperature is750℃and thecontent of WO₃is15wt%, a better yield of the target product （82.5%） is obtained.MgO/ZrO₂solid base: Macroporous MgO/ZrO₂composites were prepared by impregnation,calcination of magnesium nitrate solution. The results show that the macroporous zirconiasupports have3D ultrathin layer and the MgO nanoparticles cover on the3D zirconia layer. Then,the macroporous MgO/ZrO₂solid base catalyst exhibits a better activity of transesterification. Abetter yield of the target product （65%） is obtained when the content of MgO is50wt%and thecalcination temperature is600℃.