NICKEL SUPPORTED ON NATURAL SILICATES - ACTIVITY AND SELECTIVITY IN SUNFLOWER SEED OIL HYDROGENATION

Supported nickel catalysts have been prepared by two different methods on several clays. The precursors were studied by temperature-programmed reduction and subsequently reduced in the temperature range 350-500-degrees-C. Metal areas were determined by transmission electron microscopy and X-ray diffraction. The chemical state of the nickel prior to reduction was investigated by X-ray photoelectron spectroscopy. In the reaction of triglyceride hydrogenation of sunflower seed oil, catalysts prepared by precipitation show a larger metal area and activity than those prepared by impregnation. Activity was almost independent of the nature of the support, whereas differences in the selectivity were ascribed to differences in the morphology of the support.