Perfomances of different additives on NiO/[gamma]-Al^sub 2^O3 catalyst in CO methanation

Abstract

In this work, NiO/γ-Al₂O3 catalyst with different additives prepared by excessive dipping method, was investigated in CO methanation in an attempt to improve the reaction activity and enhance the anti-coking property. The influences of additives, such as Zr, Co, Ce, Zn and La, on catalysts in performance of CO methanation were studied in a fixed-bed reactor. The catalysts were characterized by XRD, H2-TPR, H2-TPD and CO-TPD. The results showed that the addition of the additives could promote the dispersion of nickle species on support and decrease the crystallite size of Nickel species. The reduction temperatures of catalysts were all reduced except the one with Mg. The catalytic results showed that additives improved the reaction activity of CO methanation. Especially, the addition of La gave the best catalytic performance of 100 % CO conversion and 99.61 % CH4 selectivity, respectively. The space-time yield of CH4 was achieved as high as 2134.5 g kg ^-1 h^-1.