Pyridine assisted desilication of mordenite

Abstract

Pyridine assisted alkaline desilication has been elaborated as new post-synthetic modification strategy of mordenite. The addition of pyridine during the desilication treatment revealed to impact materials properties through a dual action on textural and chemical properties; substantially different in comparison to the classical alkaline treatment or CTAB assisted desilication. As far as texture is concerned the use of pyridine permits to greatly modify the desilication scheme, hence yielding aggregates of smaller zeolite particles with substantially higher amount of external silanols. The presence of pyridine in the as-synthesized mordenites allows to in situ generate extra-framework aluminium (EFAL) species during final calcination step. Both of these features, smaller particle size and the presence of EFAL species improve catalytic properties considerably. Whilst the achievement of smaller particles reduces diffusion path length, the presence of EFAL species allow for exalting acidity and hence catalytic activity in n-hexane cracking and propene transformation.