CATALYTIC OXIDATION OF VOLATILE ORGANIC COMPOUNDS (n-HEXANE, BENZENE, TOLUENE, o-XYLENE) PROMOTED BY COBALT CATALYSTS SUPPORTED ON γ-Al2O3-CeO2

Cobalt catalysts supported on gamma-alumina, ceria and gamma-alumina-ceria, with 10 or 20% wt of cobalt load, prepared by the wet impregnation method and characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), field emission transmission electron microscopy (FETEM), N-2 adsorption-desorption isotherms (BET/BJH methods), energy-dispersive X-ray spectroscopy (EDX), X-ray photoemission spectroscopy (XPS), O-2-chemisorption and temperature programmed reduction (TPR) were used to promote the oxidation of volatile organic compounds (n-hexane, benzene, toluene and o-xylene). For a range of low temperatures (50-350 degrees C), the activity of the catalysts with a higher cobalt load (20% wt) was greater than that of the catalysts with a lower cobalt load (10% wt). The Co gamma-Al2O3-CeO2 catalytic systems presented the best performances. The results obtained in the characterization suggest that the higher catalytic activity of the Co-20/gamma-Al2O3-CeO2 catalyst may be attributed to the higher metal content and amount of oxygen vacancies, as well as the effects of the interaction between the cobalt and the alumina and cerium oxides.