The series of mono-metallic and bi-metallic catalysts have been prepared by impregnating with solutions containing compound of H2PtCl5,Re(NO3)3 and 1ml HCl (0.1 mol). The activity and selectivity of the catalysts have been determined under conditions at 450-5000C° 15-30atm. Molar ratio H2/C7H16=5 and VVH=1.5/h for converting n-heptane. Under these experimental conditions it has been established that the conversion of n-heptane into branched aliphatic isomers is catalyzed by a bifunctional mechanism. The results show that when Nb is present, the catalysts are much more stable and have much higher selectivities for isomerization reaction. At a given conversion the bimetallic catalysts produce much lower concentrations of cracked products. It is shown that Re modifies the acidity of the support, resulting to higher selectivity for isomerization and lower selectivity for cracking and also modifies the properties of the Pt.

Keywords:n-heptane,Platinum,Rhenium,Gamma-Alumina,H2PtCl5,Re(NO3)3,HCl