SUPPORTED RANEY CATALYSTS. I. RANEY Pt-Cu/Al2O3 CATALYSTS.

The authors studied the formation, structure and physicochemical properties of Raney Pt from a Pt-Cu alloy supported on gamma -Al//2O//3. According to S. A. Kiperman et al. , the promotion of group VIII metals by group IB metals has a significant effect on their activity and selectivity in hydrocarbon transformations such as isomerization, hydrogenolysis, aromatization, and dehydrocyclization. The high activity for Pt//R/Al//2O//3 catalysts may be attributed to the following factors: (1) The removal of copper and the partial dissolution of alumina should alter the specific surface and porosity of the catalysts and facilitate the migration of platinum atoms over the surface. The dimensions of the metal particles and the efficiency factor may be altered in this case. (2) A total of 0. 2-0. 8 wt. % residual copper remains. Copper adatoms may act as promoters.