SELECTIVE ALKYLATION OF TOLUENE OVER BASIC ZEOLITES - AN IN-SITU INFRARED SPECTROSCOPIC INVESTIGATION

In situ infrared spectroscopy was used to study the sorption and react ion of toluene and methanol over various alkali exchanged X zeolites. The size of the metal cations controls the preference of sorbing metha nol or toluene. The smaller the cation, the higher the preference for methanol is. A balanced sorption stoichiometry of the reactants, the i ntermediate conversion of methanol into formaldehyde de and the strong polarization of the methyl group of toluene are critical to catalyze side chain alkylation of toluene. These requirements are best met with very basic zeolites such as the Cs-X and Rb-X. (C) 1997 Academic Pres s.