Preparation of Pt/activated carbon and Pt/alumina catalysts by impregnation with platinum complexes

Abstract

Activated carbon and alumina catalysts were prepared by impregnation with solutions of platinum compounds differing substantially in the nature of their interaction with the supports: chloroplatinic acid (dissolved in water or acetone), tetraammineplatinum dichloride, and tetrakis (triphenylphosphine)platinum complex. The relations between the course of impregnation, distribution of platinum across the catalyst grain, and the activity of the catalyst in liquid phase hydrogenations were studied. Lower adsorption rates and amounts of the platinum compound adsorbed on the support bring about a more uniform platinum distribution across the grain. Catalysts with a uniform distribution exhibit higher activities than those with nonuniform distribution. The highest activity was achieved with Pt/alumina catalysts prepared from triphenylphosphine platinum comlex thermally treated in oxygen atmosphere prior to the reduction.