The catalytic reaction of NO with meso-carbon microbeads (MCMB) of ultrahigh surface area (3187 m 2 /g) in the presence of 20 wt% supported Cu was investigated. High conversions of NO were obtained at 330°C, higher by a factor of about six than those over Cu/activated carbon for the same amount of catalyst. The NO conversion decreased because of sintering with increasing decomposition temperature of MCMB impregnated with Cu(NO 3 ) 2 . A mechanism for the NO+C reaction was suggested by calculating the activation energy barriers of the possible elementary steps using the bond-order conservation method. One concludes that the NO dissociation aided by C and the disproportionation of NO are the preferred pathways of the reaction.