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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.
Three kinds of promoters were prepared by adding additives (Co, Ir or Pt) to NiMgAl supported Ni catalysts. The hydrogenation temperature reduction (H2-TPR) and CO2 / CH4 temperature- -TPSR) and CO2 temperature-programmed desorption (CO2-TPD) were used to characterize the catalysts.The effects of additives on the catalyst performance were evaluated by dry methane reforming experiments.A small amount of Pt or Ir promoter could reduce the activity of Ni The reduction temperature and the reaction performance were improved.The samples with additives added could reduce the activation energy of the reaction compared with the original NiMgAl catalyst.The activation energy of the catalyst with Co or Ir additive was significantly lower than that of NiMgAl catalyst.NiMgAl catalyst The activation energy of NiPtMgAl catalyst with Pt additive was reduced to 26.4 kJ · mol-1 with the activation energy of 51.8 kJ · mol-1. The catalyst prepared by adding Pt promoter into NiMgAl catalyst had better catalytic activity and lower activation The results of CH4-TPSR and CO2-TPSR show that addition of Pt promoter can enhance the activation ability of CH4 at lower temperature (compared with NiMgAl catalyst) and form more carbon species on the catalyst surface. Show, add additives catalysis Compared with the samples increased NiMgAl adsorption / desorption of CO2 in the reaction temperature range.