In situ DRIFTS studies on CuO-Fe2O3 catalysts for low temperature selective catalytic oxidation of ammonia to nitrogen

A series of CuO-Fe 2 O 3 composite oxides were successfully prepared for low temperature selective catalytic oxidation of ammonia (NH 3 -SCO). Higher Cu/Fe ratio in CuO-Fe 2 O 3 catalysts led to higher activity for NH 3 oxidation and the lower Cu/Fe ratio improved the N 2 selectivity. The optimal catalyst with a Cu/Fe molar ratio of 5:5 displayed a low complete conversion temperature ( 2 selectivity (>91%). H 2 -TPR results indicated that the synergistic effect existed between Fe 2 O 3 and CuO, which was beneficial to the catalytic performance. The results of the DRIFTS showed that NH 3 -SCO reaction mainly followed the internal SCR (i-SCR) mechanism. The adsorbed NH 3 was first activated and reacted with atomic oxygen to form the nitrosyl (-HNO). Then the -HNO was oxidized by oxygen atoms from O 2 to form NO species. Meanwhile, the in situ -formed NO could react with -NH 2 to form the main product of N 2 .