三维微纳米结构稀土氧化点物的控制合成与表征-化学工程专业毕业论文.docx

广东工业大学硕士学位论文关键词：氧化铈；氧化镧；水热t溶剂热法；形貌控制；催化作用 广东工业大学硕士学位论文 关键词：氧化铈；氧化镧；水热t溶剂热法；形貌控制；催化作用 II 万方数据 AbstraetA Abstraet A bstract Rare earth materials such cerium oxide and lanthanum oxide have the unique characteristic of optics，electricity and magnetism，which are widely used in optical， magnetic，catalytic，medical and agricultural fields。The activities of the rare earth materials influenced by the morphology，size，micro—structure and surface properties． In this thesis，we focused the controlled synthesis of Ce02 and La203 with controllable shape and size．We applied hydrothermal and solvothermal methods tO synthesis of 3D micro／nanostructure Ce02 and La203 and further evaluated their catalytic activities for toluene catalytic combustion over Ce02，‘La203 and three-way catalytic purification Pt—Rh—Pd／Ce02．The obtained results listed following： (1)Ce02 with different morphologies were synthesized successfully by changing the type and concentration of precursor，solvent composition，type and concentration of carboxylic acid and other conditions：spherical Ce02 was synthesized successfully through hydrothermal method under CeClffPVP／acetic acid／distilled water／urea reaction system(HTS)；spherical Ce02 was prepared successfully through solvothermal method with a reaction system of Ce(N03)3／PVP／ethylene glycol／distilled water／propionic acid (STS)．The specific surface area of Ce02 obtained form STS is 1 33 m2／g for flesh sample (calcinated at 500。C)，after aging(calcinated at 1 000。C)，the surface decrease to-7 m。／g；flower—like Ce02 with narrow pore size distribution was synthesized successfully through solvothermal method under reaction system of CeCl3／PVP／ethylene glycol／distilled water／propionic acid／KOH(STF)，of which KCl is considered hard template and plays key role in the formation of mesoporous． (2)To further improve the micro-structure of Ce02，we used HN03 to treat precursors and finally obtained etched ceria．The XRD patterns show that the etcbed ceria has weaker diffraction pea