碳酸铵加入量对共沉淀法制备LaMnAl_(11)O_(19-δ)催化剂的影响  

Influences of Amounts of Salvolatile on Catalytic Activity of LaMnAl_(11)O_(19-δ) Catalysts Prepared by Co-precipitation Method

作　　者：郑建东[1] 任晓光[1] 宋永吉[2] 于君英[1] 沈国良[3] 

机构地区：[1]北京化工大学化学工程学院,北京100029 [2]北京石油化工学院,北京102617 [3]沈阳工业大学石油化工学院,辽宁辽阳111003

出　　处：《稀土》2007年第5期40-44,共5页Chinese Rare Earths

基　　金：国家自然科学基金项目资助(20476012);北京市属;市管高校人才强教计划项目资助(BJJWR20051102)

摘　　要：以甲烷催化燃烧为目标反应,采用以碳酸铵为沉淀剂的共沉淀法制备了Mn取代的镧六铝酸盐催化剂。在不同的焙烧温度下通过SEM、XRD进行物相分析,确定了最佳焙烧温度。借助于BET、FT-IR、XRD进行了物性表征,研究了不同碳酸铵加入量下所制备催化剂的化学结构及其对甲烷催化燃烧活性的影响。结果表明,焙烧温度在1200℃左右焙烧4h可以形成完整的六铝酸盐晶型。当n(碳酸铵)/n(M2+)(其中M2+为带两个正电荷的金属离子)=1.5时,所得催化剂的活性最高,起燃温度(T10%)为471℃,完全转化温度T90%为662℃。The co--precipitation method was employed to prepare LaMnAl11O19-8 for methane combustion by using salvolatile as precipitant. The catalysts at various cacination temperature were studied to determine the optimal cacination temperature by means of XRD,SEM techniques. The influences of amounts of salvolatile on the structure and thermal stability of hexa-- aluminates and the catalytic activity for methane combustion over them were investi- gated by means of FT--IR,XRD,BET techniques. The results showed that the full crystal phase of hex--aaluminates with good activity were formed when catalysts were cacinated at 1200℃ for 4 h. Salvolatile was a good precipitant in the process of co--precipitation. At the precipitation temperature of 90℃ and the n（salvolatile）/n（M^2＋）of 1.5, the catalyst had high activity and its light--off T10% was 471 ℃, total conversion T90% was 662℃.

关 键 词：甲烷 催化燃烧 六铝酸盐 共沉淀法 碳酸铵 

分 类 号：O643[理学—物理化学] O614.33[理学—化学]