La_xSr_(1-x)FeO_3催化剂的制备及其催化还原SO_2性能的研究  

Preparation of La_xSr_(1-x)FeO_3 Catalyst and Its Performance for Catalytic Reduction of SO_2 with CO

作　　者：秦毅红[1] 孙立国[1] 张党龙 黄磊[1] 

机构地区：[1]中南大学冶金与环境学院,湖南长沙410083

出　　处：《分子催化》2016年第1期54-61,共8页Journal of Molecular Catalysis(China)

基　　金：低浓度二氧化硫烟气治理(NO.738010004)~~

摘　　要：采用柠檬酸配合溶胶凝胶法制备了不同La、Sr比例的La_xSr_(1-x)FeO_3催化剂样品,通过X射线衍射(XRD)、比表面积测定(BET)、CO-程序升温还原(CO-TPR)、SO2-程序升温脱附(SO2-TPD)、O2-程序升温脱附(O2-TPD)的方法对催化剂的结构和物理化学性质进行了表征.综合表征结果分析,通过柠檬酸配合法成功制得了具有典型钙钛矿结构的LaxSr1-xFe O3系列复合氧化物;在La Fe O3的结构中A位(La)掺杂替换少量的Sr,可以增大催化剂的比表面积、提高氧化物结构中氧空位的数量、促进反应气体在催化剂中完成反应,大大提升了SO2的催化还原转化效率.实验结果表明,当x为0.8时,CO催化还原SO2的转化率最高,在空速为24 000 m L/(g·h),温度600℃时,转化率达到95%,取得了良好的催化效果.A series of LaxSr（1-x）FeO3 catalysts was prepared by a citric acid sol-gel method,and the structural and physicochemical properties of catalysts were characterized by X-ray powder diffraction（ XRD）,BET surface area,CO temperature-programmed reduction（ CO-TPR）,SO2temperature-programmed desorption（ SO2-TPD）,O2temperature-programmed desorption（ O2-TPD）. The XRD results showed that the LaxSr（1-x）FeO3 samples prepared by citric acid sol-gel method had the typical perovskite structure. A small amount of Sr2 ＋substituted La3 ＋in A-site increased the BET surface area and oxygen vacancy of the catalyst. In addition,the substitution promoted the CO and SO2 enter the LaxSr（1-x）FeO3 lattice,which improved the SO2 conversion. Of all of these catalysts,the La0. 8Sr0. 2Fe O3 exhibited the best performance in catalytic reduction SO2 with CO. When temperature was 600 ℃,space velocity（ GHSV） was 24 000 m L /（ g·h）,the conversion raised to 95%,achieved good results.

关 键 词：柠檬酸配合 钙钛矿 催化还原 氧空位 掺杂 

分 类 号：O643.32[理学—物理化学]