FT-infrared band analysis and temperature programmed dessorption for the Y, L and ferrierite zeolites.

With the aim to qualifying and quantifying the acidity of the Y, L and ferrierite zeolites, an infrared band analysis of pyridine adsorption and programmed temperature dessorption measurements were carried out to a set of nine samples of the Y, L and ferrierite zeolites. The infrared spectra before and after the pyridine adsorption process had revealed that the ferrierite zeolite shows, almost in the totality, Brönsted acid sites. The Y and L zeolites present, also, significative concentrations of Brönsted and Lewis acid sites. These facts allow to conclude that zeolite ferrierite is the strongest acid zeolite among these three types.