氧化镁表面修饰稀土催化材料的制备和气敏性能  

Preparation and gas sensing property of rare-earth catalytic material modified by MgO

作　　者：白守礼[1] 刘志勇[1] 石冰洁[1] 马丽景[1] 杨鹏程[1] 李殿卿[1] 陈霭璠[1] 

机构地区：[1]北京化工大学理学院,北京100029

出　　处：《中国科学（B辑）》2009年第12期1603-1609,共7页Science in China(Series B)

基　　金：国家自然科学基金(批准号:50702004;50872007);北京市自然科学基金(批准号:8091003;8082018)资助

摘　　要：本文采用湿化学过程的柠檬酸络合法、可控化学沉淀法和溶胶-凝胶法合成了纳米复合金属氧化物LaFeO3,利用各种分析方法对材料的物性和结构进行了分析和表征;并测定了材料对氧化性气体和还原性气体的气敏性能.研究结果表明LaFeO3复合物对NO2在350℃灵敏度高达127.83,特别通过添加MgO对基材进行表面修饰灵敏度提高到845.37,约添加前的70倍.本文还进一步考察了添加质和添加量对基材的结构和气敏性能的影响,并通过研究材料表面对气体的吸脱附性能和元素电子结合能的变化对敏感作用机制进行了深入分析和探讨.The LaFeO3 nanocomposites were synthesized by chemical controlled co-precipitation, citric acid and sol-gel methods. Their exact composition, crystallite size, surface area, is characterized and analized by EDX, XRD, SEM and BET. The experimental results showed that LaFeO3 exhibited high sensitivity of 127.83 at 350℃ to 200 μg·g^-1 NO2, especially, the highest sensitivity reached 845.37 for MgO modified LaFeO3. The introduction method, nature and loading of additives were studied. The gas sensing mechanism of LaFeO3 for NO2 was also discussed by TPD and XPS analysis.

关 键 词：LAFEO3 结构 NO2 CO 气敏性能 

分 类 号：O643.36[理学—物理化学]