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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.
The La_xSr_ (1-x) FeO_3 catalyst samples with different La and Sr ratios were prepared by citric acid and sol-gel method and characterized by XRD, BET, CO-TPR ), SO2-temperature programmed desorption (SO2-TPD) and O2-temperature programmed desorption (O2-TPD) were used to characterize the structure and physico-chemical properties of the catalyst.According to the results of comprehensive characterization, A series of LaxSr1-xFe O3 composite oxides with typical perovskite structures were obtained. A (La) doping substitution of a small amount of Sr in the structure of La Fe O3 can increase the specific surface area of the catalyst and improve the structure of the oxide Oxygen vacancies to promote the reaction gas to complete the reaction in the catalyst, greatly improving the catalytic reduction conversion efficiency of SO2.The experimental results show that when x is 0.8, the conversion rate of CO catalytic reduction SO2 highest, at airspeed of 24 000 m L / (g · h). When the temperature was 600 ℃, the conversion rate reached 95%, and a good catalytic effect was obtained.