SEQUENTIAL ADDITION OF H2O2, PH AND SOLVENT EFFECTS AS KEY FACTORS INTHE OXIDATION OF 2,4,6-TRICHLOROPHENOL CATALYZED BY IRON TETRASULFOPHTHALOCYANINE

The efficiency of the H2O2 oxidation of 2,4,6-trichlorophenol (TCP) ca talyzed by iron tetrasulfophthalocyanine (FePcS) is highly dependent o n the pH value of the reaction mixture, the local hydrogen peroxide co ncentration and the organization of FePcS molecules in solution. Among the several forms of FePcS in aqueous solutions (dimer or monomer), m onomeric FePcS is proposed to be the catalytically active complex. The key role of the organic co-solvent (acetonitrile, acetone, alcohol,.. .) is to shift the dimer/monomer equilibrium toward monomeric FePcS, t he efficient catalyst precursor. A stepwise addition of hydrogen perox ide significantly improves the conversion of TCP and allows a low cata lyst loading, below 1% with respect to the pollutant, to be used.