KINETIC-STUDIES OF THE DEHYDRATION OF METHANOL OVER ALUMINOSILICATE AND GALLOSILICATE OFFRETITES

The kinetics of the dehydration of CH3OH by the hydrogen forms of thre e offretites with different contents of framework Al and Ga have been monitored by C-13 magic-angle-spinning (MAS) NMR spectroscopy. No reac tion takes place at room temperature. At 150 degrees C methanol is deh ydrated to dimethyl ether. As expected, the catalytic activity of offr etite for this reaction is lower than that of zeolite ZSM-5, and it de creases with increasing framework gallium content. The rates of the de hydration reaction are 0.045, 0.863 and 1.136 a.u.(-1) s(-1) for Ga-, Al,Ga- and Al-offretites, respectively.