The oxidation of carbon monoxide at ambient temperature over mixed copper–silver oxide catalysts

Cu₂Ag₂O₃ has been prepared by a precipitation method and evaluated for ambient temperature carbon monoxide oxidation. The Cu₂Ag₂O₃ catalyst demonstrated appreciable activity and a relationship with preparation ageing time was observed. An ageing time of 4 h produced a catalyst with the highest oxidation performance. The catalyst precursor materials, prepared by drying at room temperature, displayed initial high activity, which decreased with time on line. The precursors were transformed during CO oxidation to form the mixed oxide Cu₂Ag₂O₃ as the material was dried in situ. A comparison of the catalytic activity has been made with a representative sample of a high activity hopcalite, mixed copper/manganese oxide catalyst. On the basis of CO oxidation rate data corrected for the effect of catalyst surface area the Cu₂Ag₂O₃, aged for 4 h was at least as active as the hopcalite catalyst.