Hydroisomerization of benzene and skeletal isomerization of n-heptane have been studied using various 2 wt.% Pt-promoted solid acids such as Pt-Cs2.5H0.5PW12O40 (Pt-Cs-2.5), SiO2 supported Pt-Cs2.5H0.5PW12O40 (Pt-Cs-2.5/SiO2), Pt-SO42-/ZrO2 Pt-WO3/ZrO2, and Pt-H-beta zeolite. The catalytic activity for the formation of methylcyclopentane in the hydroisomerization of benzene was in order of Pt-Cs-2.5/SiO2 > Pt-Cs-2.5 > Pt-WO3/ZrO2 > Pt-SO42-/ZrO2. The highest activity of Pt-Cs-2.5/SiO2 among these bifunctional catalysts would be due to high ability for hydrogenation of benzene and high activity for skeletal isomerization of cyclohexane. In the skeletal isomerization of n-heptane, it was found that Pt-Cs-2.5/SiO2 was more selective than Pt-H-beta zeolite, which is known to be the most efficient catalyst for this reaction, though it was less active than Pt-H-beta zeolite. (C) 2003 Elsevier Science B.V. All rights reserved.