DECOMPOSITION OF FREON-12 AND CHLORINATED ORGANIC-COMPOUNDS OVER SUPPORTED GOLD CATALYSTS

Recently, halogenated organic compounds such as Freons have been claimed to be notorious for destruction of the global environment. In this study, catalytic decomposition of dilute halogenated organic compounds in the vapor phase was investigated by using gold catalysts. Au/Al2O3 and Au/Co3O4 showed steady high activities for oxidative decomposition of methylchloride. Au/Al2O3 also showed high activity for decomposition of Freon-12. Au/Co3O4, however, was not effective for the decomposition. These rcsults are interpreted as follows. Au/Co3O4 has only a high oxidation activity, while Au/Al2O3 has both hydrolysis and oxidation activities. It is supposed that reactants are hydrolyzed to alcohols over Al2O3 at first, and the intermediates, alcohols, are successively oxidized over supported gold. On the other hand, Au/Co3O4 has less activity for hydrolysis. Au/Al2O3 may be an appropriate catalyst for the decomposition of overall halogenated organic compounds.