catalytic reforming of n-heptane on platinum-tungsten supported on gamma-alumina

the mono-metallic and bi-metallic catalysts have been prepared by impregnating with solutions containing a compound of h2ptcl6,wo3 and 1ml hcl (0.1 mol). it should be noted that the catalysts’ activity and selectivity have been determined under these conditions : 450-5000c ,and 15-25atm by h2. for converting n-heptane , the molar ratio h2/c7h16 is 5 , and lhsv is 1.5ml/h. it has been proved that , under these experimental conditions , the conversion of n-heptane into branched aliphatic isomers is catalyzed by a bifunctional mechanism. the results indicate that in the presence of w , the catalysts have much higher selectivity and stability for isomerization reaction. at a given conversion , the bi-metallic catalysts produce much lower concentrations of cracked products. according to the tests , w modifies the support acidity resulting to the higher selectivity for isomerization and the lower one for cracking , and it also modifies the pt properties