Sol-gel Method Preparation and Characterization of La-Mo Complex Oxide Uitrafine Particle Catalyst

La-Mo complex oxide ultrafine particle catalyst has been prepared by the sol-gel method with citric acid as the complexant.The influences of preparation and thermal treatment conditions on the surface area and structure of the complex oxide particle have been studied by using DTA-TG,IR,XRD and BET surface area measurement methods.The results show that the surface area of La 2(MoO 4) 3 particle prepared by the sol-gel method is much larger than that of La 2(MoO 4) 3 prepared by the coprecipitation method.When the La-Mo gel is calcined in air,citric acid reacts violently with O 2,it produces a flash heat and results in an aggregation of the La-Mo particles.When the gel is calcined in N 2,citric acid is removed mildly and La 2(MoO 4) 3 ultrafine particles are formed.