GAO Xiao-qing, WANG Yong-zhao, LI Hai-tao, ZHAO Yong-xiang

(School of Chemistry and Chemical Engineering , Engineering Research Center for Fine Chemicals of Ministry of Education , Shanxi University , Taiyuan 030006 , Shanxi , China)

Abstract: The Ni/γ-Al₂O₃ and Ni-Mn/γ-Al₂O₃ catalysts were prepared by incipient-wetness impregnation method. The catalytic activities of the catalysts were carried out in a fixed-bed continuous flow operating system. The catalysts were investigated via the N₂ physisorption, XRD, TEM, H₂-TPR, TPD and TPSR characterizations. The results indicated that addition of manganese promoter increased nickel species dispersion and decreased the reduce temperature. After reduction, the amounts of moderate intensity CO₂ adsorption site and active surface area both increased on the Ni-Mn/γ-Al₂O₃ catalyst. As a result, the Ni-Mn/γ-Al₂O₃ catalyst showed higher catalytic activity for CO₂ methanation. Under the reaction conditions: V(CO₂)/V(H₂) = 1/4, GHSV 5000 h^-1 and atmosphere pressure, the Ni-Mn/γ-Al₂O₃ catalyst can make CO₂ completely convert into methane at 270 ℃, which is 60 ℃lower than Ni/γ-Al₂O₃ catalyst.

Key words: carbon dioxide; methanation; Ni/γ-Al₂O₃; manganese promoter;

E-mail: yxzhao@sxu.edu.cn

Journal of Molecular Catalysis, Vol. 25, Issue 1, 2011, 49~54.