HYDROGENATION OF CARBON OXIDES USING COPRECIPITATED AND IMPREGNATED NI AL2O3 CATALYSTS/

A group of Ni/Al2O3 catalysts having metal contents in the 0-16.5 wt% range were prepared using coprecipitation and impregnation methods. Th e catalysts were reduced under the same conditions; the reaction condi tions were also fixed in similar sets of experiments for better compar ison, Total surface area, total pore volume, metal surface area, and b oth the CO hydrogenation and CO2 methanation activities of the catalys ts were studied in order to compare the effect of preparation method o n structural properties as well as on catalyst activity and selectivit y. A comparison of CO hydrogenation results on catalysts with similar nickel loadings indicates that coprecipitated catalysts have higher pr oductivity and C-2-C-4 hydrocarbon selectivity, whereas impregnated ca talysts yield better olefin/paraffin ratios for the C-2-C-3 hydrocarbo ns. In CO2 methanation, coprecipitated catalysts show higher methanati on activity and lower CO production level per methane produced for all nickel loadings investigated. (C) 1997 Elsevier Science B.V.