Preparation Of Solid Acid Doping Rare Earth And Catalytic Properties

SO4₂^-/MxOysolid super acids have been hot spots in catalysts research fieldbecause of simple purification process, non-corrosion, less harm to the environment andgood catalytic activity. However, SO4₂^-/MxOysolid acids which are synthesized usingthe existing methods form smaller specific surface area and poor catalytic stability,which limits its further application. The structure of solid acids catalysts, such asspecific surface area, pore structure, morphology and chemical formation, is the mostimportant factor that influences its acid centers and acid strength. The catalytic activitycan be mainly improved by expanding specific surface area, constructing pore structureand adding transition metal ions or rare earth ions. Therefore, changing preparationmethods such as using templates, adding rare earth oxides on its modification in order toincrease the specific surface area, stability and catalytic activity has become theresearch hot spot in the field of solid acid.Collagen fiber is one kind of natural biological polymer materials, which is one ofthe largest renewable animal biomass resources and can be easily and cheaply obtained.Its structure is arranged orderly and can form pore structure easily, which can provideexcellent template for synthesizing special mesoporous structure material. Meanwhile,skin collagen fiber has some active groups （-NH2、-COOH、-OH） that can coordinatewith d, f empty orbital of metal ions. After calcining to remove templates, the fibrousstructure of solid acids arranged in order was prepared. This article mainly hasfollowing several aspects：1. Fibrous SO4₂^-/ZrO₂^-Nd₂O₃Solid super acid was prepared by using discard skincollagen fibers as template, zirconium sulfate as zirconium source, sulfuric acid as theactive agent and doping with rare earth element Nd, Ce. The crystal structure of thecatalyst surface area, pore structure, acid strength, the element electron binding energy, the functional group structure and solid acid stability were characterized by manykinds of analysis methods, like X-ray diffraction （XRD）, N2absorption stripping,NH3-TPD temperature programmed stripping, XPS, FT-IR, TG and so on. Usingesterification of acetic acid with n-butanol as a model reaction to find out the bestpreparation conditions of SO4₂^-/ZrO₂^-Nd₂O₃solid acid, as well as investigaterelationship between the catalytic performance and characterization results.2. Using the esterification reaction of acetic acid and n-butanol as template, thecatalytic activity of SO4₂^-/ZrO₂^-Nd₂O₃solid super acid was investigated by testingreaction temperature, reaction time, acid molar ratio, amount of catalyst on the outputrate. The reason of catalyst deactivation was found out through analytical means such asXRD, SEM, FT-IR. The catalytic activity was restored by acid activation. Themechanism of that esterification reaction of acetic acid and n-butanol catalyzed bySO4₂^-/ZrO₂^-Nd₂O₃solid super acid was discussed.3. SO4₂^-/ZrO₂^-Nd₂O₃solid super acid was synthesized under optimal reactioncondition, and was applied in catalyzing esterification reaction of acetic acid andethanol. The effect of reaction temperature, reaction time, acid molar ratio, amount ofcatalyst on the output rate of ethyl acetate was investigated and the optimalesterification reaction conditions were found out. Its repeating usability was examinedalso.