Decomposition of adsorbed nitromethane on [gamma ]-alumina

Abstract

Decomposition of nitromethane adsorbed on γ-alumina has been studied with IR spectroscopy, NMR spectroscopy and TPD. Nitromethane was chemisorbed as aci-anions (CH₂NO₂^-) at room temperature. At 373 K, two species, tentatively assigned to nitrosoaldehyde and a (C, N, O) adduct, have been detected which were formed by deprotonation of aci-anions. These species may be transformed to isocyanate, which was also formed at 373 K. Isocyanate was hydrolyzed to form ammonia and carbon dioxide at 473 K. The relevance of these results to the selective catalytic reduction of nitrogen oxides by hydrocarbons is discussed.