nanocatalyst was prepared in microemulsion system by using -irradiation technique. In this green procedure the reduction of platinum source has been done without chemical reducing agent. Abstract:. In this research work, Pt/Al2O3After preparing Pt nanoparticles stabilized in microemulsion system, -Al2O3 was \added to obtain Pt/Al2 nanocatalyst by precipitation procedure. This clean method was also compared with common microemulsion methods, which reduce Pt precursor by a chemical reagent. The resulted nanocatalyst samples were characterized by SEM and XRD techniques. O 3