摘要
以柠檬酸为络合剂 ,采用溶胶 -凝胶法合成了镧 -钼复合氧化物超细微粒催化剂 ,使用 DTA- TG、IR、XRD以及 BET比表面测试等表征手段 ,考察了制备条件与热处理条件对复合氧化物超细微粒形成、结构和表面积的影响。结果表明 :本方法制备的 L a2 (Mo O4) 3 复合氧化物的比表面积远远大于共沉淀法制得的类似样品的比表面积 ,在氮气气氛中分解镧 -钼凝胶中的柠檬酸 ,可有效地避免柠檬酸分解发生氧化燃烧而引起微粒烧结。
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.
出处
《稀土》
EI
CAS
CSCD
北大核心
2001年第6期13-15,共3页
Chinese Rare Earths
基金
江西省自然科学基金 ( 992 0 0 0 7)资助项目
