The deep oxidation of chlorobenzene was investigated over Pt/H-ferrierite and Pt/H-ZSM5 catalysts. Catalytic results showed that Pt/zeolite samples exhibit higher activity and lower by-products formation than Pt/gamma-Al2O3, tested for comparison. Pt/H-ferrierite resulted to be the most favorable system as it leads to the lowest formation of noxious polychlorinated benzenes. The present FT-IR investigation pointed out that the support significantly affects the combustion of chlorobenzene over Pt/zeolite catalysts, support acidity directing the activity of the system and pore structure of the zeolite determining the level and the distribution of polychlorinated compounds.