CHARACTERISTICS OF CUO-CR2O3 MORDENITE AND ITS CATALYTIC ACTIVITY FORCOMBUSTION AND NO DECOMPOSITION/

Copper and chrome oxide were co-impregnated on mordenites and characte rized by XRD, ESR, and H-2-TPR. The catalysts, subjected to a H-2/O-2 redox cycle at 500 degrees C and 750 degrees C, were examined for comb ustion of methane and acetone, and for NO decomposition. An easily red ucible Cr-Cu oxide complex was formed by the addition of chrome oxide to copper oxide on the mordenites after the redox treatment (H-2/O-2) at 500 degrees C. However, the redox treatment at 750 degrees C transf ormed the oxide complex to copper chromate. No difference was found in the activity of NO decomposition between CuO/mordenite and CuO-Cr2O3/ mordenite redox-treated at 500 degrees C. For both methane oxidation a nd NO decomposition, maximum activity appeared at CuO(7)-Cr2O3(7)/mord enite redox-treated at 750 degrees C, resulting in the formation of co pper chromate. Dealumination also increased the activities, and the ma ximum activity appeared at a silica/alumina ratio of 20-30.