铁取代六铝酸盐的制备及其对甲烷燃烧的催化性能  

Preparation of Fe-Substituted Hexaaluminate and Its Catalytic Performance for Methane Combustion

作　　者：蒋政[1] 李进军[1] 郝郑平[1] 侯红霞[1] 许秀艳[1] 胡春[1] 

机构地区：[1]中国科学院生态环境研究中心,北京100085

出　　处：《催化学报》2004年第6期485-489,共5页

基　　金：国家 8 63计划 ( 2 0 0 1AA3 2 40 5 0 );人事部留学回国人员择优基金资助项目

摘　　要：采用共沉淀 水热处理法制备了铁取代六铝酸盐 (BaFexAl12 -xO19-δ,x≤ 3)催化剂 ,并用XRD ,SEM ,UV Vis和BET等技术对催化剂进行了表征 .结果表明 ,经 10 0 0℃焙烧后催化剂开始出现少量六铝酸盐相 ,110 0℃焙烧后六铝酸盐相为主要的晶相 ,当x >3时催化剂中的杂质相不可忽略 .Fe取代六铝酸盐中的Fe主要为Oh配位 .在x≤ 3范围内 ,随着Fe取代量的增加 ,催化剂对甲烷燃烧的催化活性逐渐升高 ,其中BaFe3 Al9O19-δ的起燃温度最低 (5 15℃ ) ;继续增加Fe含量 ,催化剂的高温活性反而下降 .向Fe单取代六铝酸盐晶格中引入La制得的Ba0 5La0 5FeAl11O19-δ催化剂 ,其起燃活性与BaFeAl11O19-δ的基本相同 ,但高温活性有较大提高 .反应气组成对催化剂的活性有显著影响 ,提高O2 分压可以降低催化剂的起燃温度 ,但对高温活性的影响不大 .BaFe2 Al10 O19-δ催化剂在 80 0℃下运行 10Fe-substituted hexaaluminate (BaFe xAl 12-xO 19-δ) was prepared with co-precipitation method followed by hydrothermal treatment. The XRD and SEM results indicated that no hexaaluminate phase was formed when calcined below 1?000 ℃, and hexaaluminate was the dominant phase when calcined above 1?100 ℃. Moreover, the UV-Vis-DR result verified that Fe occupied the Oh sites in Fe-hexaaluminate structure. With the increase of Fe content (x≤3), the activity of hexaaluminate for methane combustion was raised. The most active catalyst was BaFe 3Al 9O 19-δ, the light-off temperature of which was 515 ℃. Compared with BaFeAl 11O 19-δ, the high-temperature activity of Ba 0 5La 0 5FeAl 11O 19-δ increased greatly, no obvious promotion for methane ignition activity was observed. The reactant atmosphere had impact on methane ignition activity, but slight influence on high-temperature activity due to the transport limitation. Stability experiment was carried out at 800 ℃ for 100 h, and no deactivation was detected.

关 键 词：甲烷 催化燃烧 铁取代 六铝酸盐 镧掺杂 水热合成 

分 类 号：O643[理学—物理化学]