Hydrogenation of CO 2 over Alkali Metal-Modified Ni/Al 2 O 3 Catalysts

Abstract

A group of Ni and Ni, Li/Al₂O₃ catalysts were prepared using impregnation and controlled surface reaction methods. The various steps in the preparation were characterised by IR spectroscopy. The catalysts were reduced under the same conditions, while fixed conditions were also employed for the subsequent reactions in order to effect a better comparison. The total and metal surface areas, the degree of nickel reduction and the activity of the catalysts towards CO₂ methanation were all measured in order to compare the effect of preparation method on the structural properties as well as on the catalyst activity and selectivity. Nickel catalysts modified with lithium, either by controlled surface reaction or double impregnation utilising H₂Li₂EDTA, exhibited a higher activity in CO₂ methanation than any other catalyst samples investigated.