【摘要】 采用碳酸氢铵作为沉淀剂制备二氧化铈超细粉体。X射线衍射结果表明 ,焙烧温度在 30 0～ 90 0℃时 ,所得二氧化铈纳米晶为立方晶系 ,其平均粒径随焙烧温度的升高而增大。热失重结果表明 ,样品的失重率取决于焙烧温度。反应物浓度为 0 .2 5～ 0 .3mol/L ,沉淀剂浓度为 0 .2～ 0 .4mol/L ,pH值为 7～ 8,沉淀温度为 60～ 80℃ ,焙烧温度为 60 0℃ ,可制得平均晶粒度小于 2 0nm ,分散性好的二氧化铈超细粉体更多还原

【Abstract】 Ultrafine CeO₂ powder was prepared using NH₄HCO₃ as precipitating agent. The results of X-ray diffraction show that CeO₂ nanometer crystals obtained at 300～900 ℃ are cubic crystals, of which the mean size increases with the roasting temperature. The weightlessness rate of the sample depends mainly on its roasting temperature. At a reactant concentration of 0.25～0.3 mol/L, a precipitatant concentration of 0.2～0.4 mol/L, a solution pH of 7～8, a precipitation temperature of 60～80 ℃ and a roasting temperature of 600 ℃, ultrafine CeO₂ powders can be prepared with a mean size of 20 nm and good dispersibility.更多还原