Cormerais, F. X.; Chen, Y.; Kern, M.; Gnep, N. S.; Perot, G.; Guisnet, M. J. Deeba, M.; Hall, W. J. Catal. 1979, 60, 417. Dejaifve, P.; Auroux, A.; Gravelle, P. C.; Vedrine, J. C.; Gabellca, Derouane, Dejaifve, P.; Vedrine, J.; Bolls, V.; Derouane, E. G. Turner, J. 0. J. Am. Derouane, E. G.; Nagy, J. 6.; Dejaitve, P.; van Hoof, J. H. C.; Spekman, B. P.; Forni, L. Catal. Rev.The effects of organic nitrogen compounds on the hydrodesulfurization of a catalytic naphtha were examined under conditions where the nitrogen compounds were generally unreactive. The nitrogen compounds tested as inhibitors included several alkylpyridines, 2,5dimethylpyrrole, 4-methylaniline, and benzylamine. Significant differences in desulfurization were observed which could be related to nitrogen compound structure. Comparison of alkylpyridines clearly shows a steric contribution of ring substituents. The lack of inhibition when methyl groups were attached to ring carbons adjacent to the nitrogen atom suggests adsorption of the pyridine molecule on the active desulfurization site through the nitrogen atom. Electronic effects, such as resonance stabilization, may account for the relatively small inhibition effect of sterically unhindered 4-methyianiline while the larger inhibition effects of the hindered 2,5dimethylpyrrole and benzylamine can be attributed to their greater reactivity to produce more strongly adsorbed polymeric materials and ammonia, respectively.