Cobalt catalysts supported on activated carbons: preparation and behaviour in the hydrogenation of carbon oxides

Abstract

Two activated carbons with different pore texture obtained from olive stones have been used as supports for Co catalysts. The supported catalysts were prepared from Co₂(CO)₈ following either a sublimation or an evaporation technique or from cobalt nitrate following an impregnation technique. The catalysts once reduced were characterized by H₂ chemisorption and transmission electron microscopy. H₂ chemisorption was a nonactivated process but was reversible depending on the mean particle size and the method of preparation. The supports were hydrogasified during the reduction process, which was a cause of a decrease in dispersion.

The supported catalysts were tested for the hydrogenation of CO and CO₂ and in both reactions they were structure-insensitive in the dispersion range studied here (5–32%).