Catalytic destruction of chlorinated POPs—Catalytic oxidation of chlorobenzene over PtHFAU catalysts

Abstract Catalytic oxidation of monochlorobenzene (667 ppm) in wet air was investigated over PtHFAU(5) catalysts, differing by their Pt content (from 0 to 1.1 wt.%), their Pt dispersion (for identical Pt content) and the electronic state of Pt. PtHFAU(5) catalysts show a higher activity compared to more conventional PtAl 2 O 3 and PtSiO 2 samples. For a given temperature, chlorobenzene oxidation over PtHFAU(5) is independent of the platinum particles size. On the other hand, a plateau in activity is reached from 0.4 to 0.6% Pt. Amount of polychlorinated benzenes (PhCl 2+ ) were produced in the order PtAl 2 O 3  > PtSiO 2  > PtHFAU(5). The formation of these compounds, especially PhCl 2 , over PtHFAU(5) was function on the Pt content (PhCl 2 isomers appear only from 0.6% PtHFAU), and of the electronic state of Pt. Thus PhCl 2 , were mainly found over reduced Pt 0 particles certainly through a chlorination of platinum (formation of PtCl x species). A reaction scheme for the PhCl 2 formation was proposed.