n-Heptane isomerization over Al2O3-doped Pt/WOx/ZrO2 (Pt/WZA) in comparison with PL/WOx/ZrO2 (Pt/WZ) was studied in the presence of H-2 at 200 degreesC. Higher isomerization selectivity was observed for these catalysts. The catalytic activity depends strongly on surface WOx loading and calcination temperature of WOx/Al2O3-ZrO2 (WZA) and WOx/ZrO2 (WZ) supports. The maximum activity for both Pt/WZA and Pt/WZ catalysts occurs at a WOx concentration of 10 wt.% W which is slightly higher than the theoretical monolayer capacities of WZA and WZ supports calcined at 800degreesC. Pt/WZA catalyst exhibits the higher maximum activity than Pt/WZ. The loss in activity observed at high H-2 pretreatment temperatures appears to be due to the strong interaction between Pt and reduced WOx species.