CALORIMETRIC AND IR-SPECTROSCOPIC STUDY OF ADSORPTION OF METHANOL ON ZEOLITE-LIKE ALUMINOPHOSPHATES

Electrostatic properties of zeolite-like aluminophosphates are interme diate between those of zeolites and zeolite-like silica modifications. The adsorption measurements and IR spectroscopic investigations of th e framework vibrations demonstrate that the number of the adsorption c omplexes of CH3OH with Al atoms increases in the following order: AlPO 4-5 < AlPO4-17 << AlPO4-18. The OH vibrations of methanol molecules in the first coordination sphere of the Al atoms are reflected in the IR spectra as an absorption band at 3200 cm(-1), which is not observed f or the adsorption of CH3OH on zeolites.