Copper catalysts in the selective hydrogenation of soybean and rapeseed oils: IV. Copper on silica gel,phase composition and preparation

Phase composition of a copper on silica gel catalyst was studied with X-ray diffraction analysis. Activity measurements showed three periods of activity, the first two of which were ascribed to a copper surface subjected to reduction and the third one to the reduced form of the catalyst. Hydrogenation reaction over Cu/SiO₂ catalyst has a complex pressure dependence with a rate maximum at 6 atm in the low pressure range. Preparation of the catalyst was studied. On the basis of a proposed reaction model, a catalyst mixture was prepared and tested with good results. In rapeseed oil hydrogenation, Cu/SiO₂ catalysts were shown to be superior to copper chromite catalysts. In soybean oil the two types of catalyst were rather equivalent.