| China is a country of lagre reserves and production of rare earth in the world. Special properties and effects of rare earth oxides have already caused the attention of catalysis. The properties of rare matel oxides, such as oxygen mobility in lattice, paramagnetic, basicity and variable valence of cation, are linked closely to catalyst. It not only has the catalytic properties of rare earth oxides, but also be used as an additive and catalyst promoter to improve the catalytic performance of catalyst. Therefore, rare earth materials as catalysts are widely used in many chemical processes.A new solid solution material of Pr-Zr was taken as the research object in this thesis. Its physical and chemical properties and application were analyzed. The main content includes:the preparation methods of Pr-Zr solid solution, influence of preparation condition on the formation of Pr-Zr solid solution, the reaction properties of Pr-Zr solid solution applied to the chemical chain for selective oxidation of methane to prepare synthesis gas, the selection and optimization of meso-porous Pr-Zr solid solution preparing condition, the preparation design of Au catalyst with meso-porous Pr-Zr solid solution and its application and performance analysis in CO oxidation reaction and soot combustion reaction.In order to obtain the best performance of Pr-Zr complex oxide, the Pr-Zr solid solution was prepared and the best preparation method was explored firstly. The perfect solid solution of Pr0.7Zr0.3O2-δ could be prepared after calcinating in 800 ℃ along with the following conditions:precursor salts of Pr(NO3)3·6H2O and Zr(NO3)4, preparing temperature:12 ℃, pH=12. The influence of preparation conditions on the physical and chemical properties of Pr-Zr complex oxide was analyzed. It was found that the key factors of affecting the formation of solid solution are preparation temperature and titration pH. Degradation temperature and liquor concentration will little affect the formation of perfect solid solution. But the oxygen activity of the oxide can be strengthened by extending degrading time and lowering liquor concentration. It was also found that the oxygen transfer performance is the reason that the solid solution has better redox properties.A series of Pr1-xZrxO2-δ solid solution (x=0.1,0.2,0.3,0.4,0.5,0.6,0.7,0.8,0.9) were prepared by extending this preparation method. Compared with pure Pr6O11, the grain size of Pr-Zr solid solution was obviously smaller, and its reduction peak temperature was lower, its activity stronger. The Pr1-xZrxO2-δ solid solution was applied to the chemical chain for selective oxidation of methane to prepare synthesis gas. It was found that 800 ℃ is the best calcination temperature of Pr-Zr complex oxide for selective oxidation of methane to prepare synthesis gas, and 850 ℃ is best reaction temperature to prepare synthesis gas with methane selective oxide. The Pr1-xZrxO2-δ solid solution has a higher methane transferring ratio and selection of H2and CO. More importantly, it has a good stability of circular reaction. Before and after the circular reaction, the material always keeps the structure of solid solution. The stability after multiple circular reaction is due to the increase of bulk lattice oxygen content and surface oxygen vacancies.Based on the preparation of Pr1-xZrxO2-δ solid solution, the preparing method of meso-porous Pr-Zr solid solution was proposed. The meso-porous Pr-Zr solid solution could be prepared by sol-gel process of constant temperature and humidity cultivating, drying, and calcinating along with the following condition:0.4 g/mL F127 being template, Pr(NO3)4 and ZrOCl2 being precursor salts, alcohol being solvent, sol-gel reaction temperature being 40 ℃. The effect of preparing condition on the formation of meso-porous Pr-Zr solid solution was analyzed. It was found that the key factors of preparing meso-porous Pr-Zr solid solution include:preparation method, sol-gel reaction temperature, template concentration and type. The formation mechanism of meso-porous Pr-Zr complex oxide was discussed. It was found that the mechanism of the meso-porous material belongs to synergistic action mechanism.In order to learn the application prospect of meso-porous Pr-Zr solid solution, its performance in CO oxidation reaction and soot combustion reaction was studied. The meso-porous Pr-Zr solid solution has an outstanding catalyzing effect. Compared with traditional catalysts, the high-temperature degrading temple of the meso-porous Pr-Zr solid solution behaves better reaction profiles. A complex catalyst of Au/Pr-Zr-O was prepared with the meso-porous Pr-Zr solid solution being carrier and Au being active component. The complex catalyst of Au/Pr-Zr-O was applied in CO oxidation reaction and soot combustion reaction. It was found that Au and Pr1-xZrxO2-δ have synergistic catalytic actions. As the carrier, Pr-Zr solid solution behaves good performance of high-temperature degradation, which greatly increases the reaction performance in catalytic reactions.
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