Catalytic Properties of Ni/CNTs and Ca-Promoted Ni/CNTs for Methanation Reaction of Carbon Dioxide

摘要

Nickel/carbon nanotubes (Ni/CNTs), Nickel/alumina (Ni/Al_2O_3), calcium-promoted Ni/CNTs and calcium-promoted Ni/Al_2O_3 were synthesized by impregnation method. Methanation of carbon dioxide was used as a probe to evaluate their catalytic performance. The features of these Ni-based catalysts were investigated via XRD, H_2-TPR, H_2-TPD and the N_2 adsorption-desorption isotherms. H_2-TPR showed that nickel species on Ni/CNTs was reduced more easily with respect to that on Ni/Al_2O_3, and addition of Ca can increase the content of easily reducible Ni species for Ni/CNTs. XRD and H2-TPD indicated that addition of Ca promoted dispersion for CNTs-supported catalyst. These finding ultimately enhanced catalytic activity and stability for Ni/CNTs catalyst modified with Ca.