NO reduction with CO in the presence of O-2 over Al2O3-supported and Cu-based catalysts

NO reduction with CO in the presence of O-2 was examined over various kinds of Al2O3-supported and Cu-based catalysts. The effects of loaded elements, supports and calcination temperatures on catalysis for the NO-CO-O-2 reaction system were investigated. We found that the most effective catalyst was 0.5 wt. % Cu/gammaAl(2)O(3) calcined at 773 K. The states of Cu species were characterized with XRD, UV/VIS/NIR, EPR, TPR and X-ray absorption spectroscopic techniques. Highly dispersed Cu2+ species on Al2O3 are active species for selective reduction of NO to N-2. The aggregated Cu species preferentially oxidize CO without reducing NOx, and the appearance of the aggregated Cu species resulted in drastic reduction in N-2 formation capability.