La-Mo series complex oxide ultrafine particles have been prepared successfully by the sol-gel method at low tomperature. The infiuence of preparation conditions and thermal treatment conditions on the morphology and the structure of the oxide particles has been studied by using XRD, DTA-TG, TEM, FT-IR and BET surface area measurement methods. For the preparation of the well-distributed La-Mo series complex oxide ultrafine particles with the size in the range of 40-80nm, the optimum conditions are:ncitrie/nLa+Mo=0.3, pH≤1.5, t≤500℃.
Fe2(MoO4)3 ultrafine particle catalyst has been prepared successfully by the sol-gel process at lower temperature. The influences of preparation conditions and thermal treatment conditions on the morphology and structure of the ultrafine particle catalyst has been studied by using TEM, DTA-TG, FT-IR, XRD and BET surface area measurement methods. It is shown that the BET surface area of Fe2(MoO4)3 ultrafine particle prepared by sol-gel method is much larger than that of Fe2(MoO4)3 prepared by coprecipitation method. For the preparation of the welldistribuated Fe2(MoO4)3 ultrafine particles with the size in the range of 40-80nm, the optimumconditions are : treatment temperature <673K, L/M (Citric acid/Metallic ions)=0.3 and pH<1 .0.