Ammonia interaction and reaction with Al-pillared montmorillonite: an IR study

Interaction of ammonia (both as NH(3) and ND(3)) with plain and Al(13)-pillared montmorillonite has been studied by means of IR spectroscopy. Up to seven types of hydroxyls have been identified on the basis of their behaviour, for which a tentative nature and location are proposed. Al(13)-pillars behave to some extent as alumina particles, showing e.g. basic hydroxyls. Pillars and day sheets show synergetic effects, concerning both the acidity and the reactivity of the PILC. On the one hand, new acidic hydroxyls are formed, some of which undergo proton transfer to ammonia. On the other hand, Si-O-Al bridges at the border region between the clay sheet and the pillar are cleaved by NH(3), with formation of non-acidic AlNH(2), species. (C) 1998 Elsevier Science B.V.