The catalytic activity of Pd and Pd-M bimetallic catalysts (M = Cr, Cu, Pt, Ag) on different solid supports for isomerization in gas phase of a mixture of pinenes poisoned with 4000 pmm of sulfur as thiophene was studied. This mixture was used as a model of crude sulfate turpentine (CST), which is a cheap and valuable source of pinenes. The major product of this reaction is p-cymene, an important product in chemical industry. It was found that Pd-Pt/ SiO2-Al2O3 gives a selectivity of 65-70% and a conversion of 98%. Molecular sieves as catalyst support were also investigated but the activity was not as better as the SiO2 or SiO2-Al2O3 for the targeted reaction