助剂对NiMgAl催化剂的结构和甲烷二氧化碳重整反应性能的影响(英文)  

Effects of Promoter on NiMgAl Catalyst Structure and Performance for Carbon Dioxide Reforming of Methane

作　　者：郭章龙 黄丽琼[1,2] 储伟[1] 罗仕忠[1] 

机构地区：[1]四川大学化学工程学院,成都610065 [2]云南开放大学化学工程学院,昆明650223

出　　处：《物理化学学报》2014年第4期723-728,共6页Acta Physico-Chimica Sinica

基　　金：supported by the National Key Basic Research Program of China(973)(2011CB201202)~~

摘　　要：向担载镍基催化剂NiMgAl中添加助剂(Co,Ir或Pt)制备了三种助剂促进型催化剂,通过氢气程序升温还原(H2-TPR),CO2/CH4程序升温表面反应(CO2/CH4-TPSR)和CO2程序升温脱附(CO2-TPD)等方法对催化剂进行表征.助剂对催化剂性能的影响通过甲烷干重整实验进行评价.添加少量的Pt或Ir助剂可以降低Ni活性组分的还原温度和提高反应性能.添加助剂的样品与原始NiMgAl催化剂相比能够降低反应的活化能,添加Co或Ir助剂的催化剂与NiMgAl催化剂相比活化能有了明显的降低.NiMgAl催化剂的活化能为51.8 kJ·mol-1,添加Pt助剂的NiPtMgAl催化剂活化能降至26.4 kJ·mol-1.NiMgAl催化剂中添加Pt助剂制备的催化剂具有较好的催化活性和较低的活化能.CH4-TPSR和CO2-TPSR结果表明添加Pt助剂可以在更低的温度下(与NiMgAl催化剂相比)提高CH4的活化能力,并在催化剂表面形成更多的碳物种.CO2-TPD结果显示,添加助剂的催化剂与NiMgAl样品相比在反应温度区间内增加了CO2的吸附/脱附量.Catalysts were prepared by adding different types of promoter （Co, It, or Pt） to the supported nickel catalyst NiMgAI samples. These catalysts were characterized by H2 temperature-programmed reduction （H2- TPR）, CO2/CH, temperature-programmed surface reactions （COJCH4-TPSR）, and CO2 temperature- programmed desorption （CO2-TPD）. The effects of the catalyst structure on catalytic performance in the methane dry reforming reaction with carbon dioxide were investigated. The addition of a small amount of promoter （Pt or Ir） can lower the reduction temperature of the nickel active component, and enhance performance in the methane dry reforming reaction. The catalysts with Co or Ir promoter feature lower activation energies than the unmodified NiMgAI catalyst. The activation energy was 51.8 kJ. mo1-1 for the NiMgAI sample, decreasing to 26.4 kJ· mol-1 for the NiPtMgAI catalyst, which showed overall better catalytic performance. Results of CH4-TPSR and CO2-TPSR demonstrate that the NiPtMgAI catalyst can generate more active carbon species on the catalyst surface. The CO2-TPD results show that adding a promoter can increase the CO2 adsorbed/desorbed amount compared with the unmodified NiMgAI catalyst over the same reaction temperature range.

关 键 词：甲烷二氧化碳重整 镍基催化剂 铂助剂 催化活性 活化能 程序升温表面反应 

分 类 号：O643.32[理学—物理化学]