Reaction of NO with carbonaceous materials: III. Influence of the structure of the materials

Four carbonaceous materials: carbon black, activated carbon, fullerene blac k and graphite, were employed in the NO-carbon reaction in order to study i ts structure sensitivity. The carbon structures were characterized by TEM a nd XRD analysis. The results obtained indicate that the internal structure of the samples employed greatly affects the reactivity of the samples towar ds NO. The reaction of NO with graphite shows a higher reaction rate per un it surface area than the reaction with the three amorphous carbons. The dif ferences in reactivity between graphite and the amorphous carbons point to the presence of two kinds of active sites attributed to defective carbon si tes and the carbon sites at the basal planes, respectively. The relative co ncentration of the different active sites depends on the structure of carbo naceous materials. The results obtained strongly suggest that the reaction between NO and carbon is a structure sensitive gas-solid reaction. (C) 2000 Elsevier Science Ltd. All rights reserved.