Comparison of different preparation methods of PtIr, PtIrSn and PtIrGe catalysts for hydrocarbon transformation

Introduction Heterogeneous catalysts are employed in 80 % of ind ustrial catalytic processes with multimetallic formulations which enhance the perfor mances of catalysts [1]. Nowadays, an increased attention has been paid to preparation me thods using “Controlled Surface Reactions (CSR)” [2, 3]. These catalysts are rather active an d selective in various reactions, for example in hydrocarbon transformation [3, 4]; promisingly r esult in cleaner products and safer processes producing less wastes. The full character ization of such catalysts requires a combination of physico-chemical methods with cataly tic tests. Our aim was to investigate bimetallic Pt-Ir catalysts prepared by two differen t methods, namely classical successive impregnation and by organometallic grafting [2, 4] as well as to study the effect of a third metal (Ge or Sn) added in both cases by organometal lic grafting method.