稀土改性镍催化剂对CO_2甲烷化反应的影响

Influence of Modified Nickel-catalyst on CO_2 Methanation

以稀土为助剂 ,金属镍为活性组份 ,研究了不同稀土对镍催化剂的改性作用 ,同时用活性比表面、H2 -TPD、CO2 - TPD及 XPS等方法对催化剂进行了表征。结果表明 ,稀土对镍催化剂的 CO2 甲烷化活性有明显的促进作用 ,其中以稀土 Sm的改善效果最好 ;海泡石和 Sm既能增大镍催化剂的活性比表面积 ,又能提高 H2 和 CO2 的吸附量 ,同时降低反应的活化能 ,增大镍上的电子云密度。

The nickel-catalyst modified by rare earth was investigated.The surface behaviors of the catalysts were characterized by CO chemisorption,H 2-TPD,CO 2-TPD and XPS.The results show that the catalytic activity is improved by the modification of rare earth,and Sm has the best role.Sepiolite and Sm not only can increase the active surface area and the amounts of adsorbed H 2 or CO 2,but also can decrease the activation energy and the binding energy of nickel.