【摘要】 以共沉淀法制备Ce-Zr-O固溶体,在液相反应阶段、干燥阶段和灼烧阶段分别采取快速喷射和加入表面活性剂、正丁醇共沸蒸馏脱水以及选择适当的灼烧温度等手段控制团聚体的生成.制得超细颗粒Ce_0.5Zr_0.5O₂固溶体.XRD,TEM及比表面积等的测试结果表明,该催化剂是面心立方结构、较高比表面的超细颗粒.Zr⁴⁺掺杂较均匀的超细固溶体,其Raman光谱中晶格畸变带来的t_2g活性振动模式分裂谱峰较弱,说明晶体结构规整性较大.催化甲烷燃烧的活性测试结果也证实超细颗粒Ce_0.5Zr_0.5O₂固溶体的催化活性大于常规共沉淀法制备的催化剂.更多还原

【Abstract】 Ce-Zr-O solid solution was prepared by coprecipitation with control of agglomeration. Ce4+ and Zr4+ mixed solution was spurted into the precipitant of surfactant added in the stage of reaction of liquid phase. After elimination of water by means of heterogeneous azeotropic distillation process with n-butanol,the powder was calcined at different temperatures. The result mixed oxide is face-centered cubic analyzed by XRD. The solid solutions are fiberlike ultrafine particles from TEM pictures. The super-micro particles have larger specific surface than the particles prepared by common coprecipitation. In the Raman spectra,splitting peaks of t2g active vibration mode resulted by distorted lattice are weaker than the samples prepared by common coprecipitation process. Raman spec-troscopic research show that the crystal structure of the ultrafine solid solution has better degree of order and Zr4+ ion enters into the lattice more even. Super-micro powder of Ce0. 5Zr0.5O2 solid solution is more active to catalyze the combustion of methane than the catalyst synthesized by common coprecipitation method.更多还原