The mechanism of the selective NOx adsorption on 12-tungstophosphoric acid hexa-hydrate

Abstract The paper describes the study of HPW, using conditions simulating as close as possible to a real car exhaust. The amounts of NO absorbed and desorbed prove very high with NO and NO 2 in molar ratio. XRD suggests that the structure is conserved following complete saturation by NO x . The adsorption mechanism proceeds via a substitution of the water molecules by NO x to form an [H + (NO 2 - ,NO + )] complex.