In situ infrared study of the modification of the surface of activated carbon by ammonia, water and hydrogen

The reaction of an oxidised activated carbon with gaseous ammonia converts surface cyclic anhydride groups to amide and ammonium carboxylate species, which at elevated temperatures decompose to nitrile. Amine and alcohol species are also adsorbed products of ammonia treatment. Cyclic anhydride groups were hydrolysed by water to carboxylic acid groups, which were also possibly formed in conjunction with alcohol groups by lactone hydrolysis. Hydrogenation of carbon, catalysed by nickel, converted aromatic ether, epoxy and carbonyl species to polynuclear aromatic ring systems which were free of oxygen-containing substituents.