中文摘要：

采用共沉淀-超临界干燥法制备了混合取代型La0．8Sr0．2FeMn1．5Al9．5O19-δ（LSFMAO）六铝酸盐气溶胶甲烷燃烧催化剂，并采用XRD、BET、SEM、TPR等技术研究了超临界干燥和高温焙烧对材料结构和催化性能的影响．超临界干燥处理的前驱物经1200℃焙烧后，得到磁铅石型六铝酸盐气溶胶，其具有较高的比表面积（16m^2·g^-1）和甲烷燃烧活性；然而高温（1300-1400℃）老化导致该六铝酸盐严重烧结，比表面积和催化活性急剧下降．研究结果表明，对一定温度范围内（≤1200℃）焙烧的六铝酸盐催化剂，超临界干燥法有助于改善其热稳定性和催化活性，但高温（〉1200℃）老化后，催化剂的抗热烧结和催化性能主要由材料的组成和固有结构性质决定．

英文摘要：

La0.8Sr0.2FeMn1.5Al9.5O19-δ（LSFMAO） hexaaluminate aerosol was prepared by co-precipitation combined with supercritical drying and high temperature calcinations. XRD, SEM, BET, TPR characterizations as well as methane catalytic combustion were performed to investigate the effects of supercritical drying and high temperature calcinations on the structure and reactivity of the catalysts. The results indicated that the plate-like LSFMAO hexaaluminate aerosol was formed after calcination of the aerosol precursors at 1200℃. The as-prepared LSFMAO hexaaluminate possesses large specific surface area （16 m^2·g^-1） and excellent catalytic combustion activity at high gas space velocity. However, further calcinations of the LSFMAO hexaaluminate at 1300 ℃and 1400 ℃ resulted in severe sintering and reduction of catalytic activity. These results revealed that supercritical drying was helpful to promote the combustion activity and resist sintering of the LSFMAO hexaaluminate up to 1200℃ above which the sintering resistance and redox performance of LSFMAO hexaaluminates were mainly determined by the components and intrinsic properties.