Total oxidation catalysts based on manganese or copper oxides and platinum or palladium II: Activity, hydrothermal stability and sulphur resistance

摘要

Deactivation of catalysts based on either manganese oxides, copper oxides, platinum, palladium or combinations of these metal oxides and noble metals supported on #gamma#-alumina was studied. The activity of the catalysts of the oxidation of carbon monoxide, anphthalene and methane, in a mixture resembling the flue gases from wood combustion, was measured before and after exposure of the catalysts either to a temperature of 900 deg C in the presence of steam or to sulphur dioxide. Most of the mixed catalysts were more resistant to hydrothermal and sulphur treatments than the catalysts with a single active component. After the hydrothermal treatment the activity of the MnO_x catalyst was enhanced. Also, the hydrotreated mixed MnO_x-Pd and CuO_x-Pd catalysts were improved for the oxidation of carbon monoxide and naphthalene. Among the catalysts studied, the MnO_x-Pt, CuO_x-Pd catalysts, with a oxide and a noble metal loading of 10 and 0.1 molprecent/#gamma#-alumina, respectively, had the bestcombination of activity, thermal stability and resistance to sulphur treatment.