DEHYDRATION OF ISOPROPANOL OVER ZEOLITE CATALYSTS

The dehydration of isopropanol over cation-exchanged forms of Zeolite X and Zeolite Y has been studied at 140—200° C using an adaptation of the micro-catalytic reactortechnique. The activity sequence at 160°C was: [formula ommitted], where CaY-27 etc. indicates 27% replacement of Na+ by Ca2+ in NaY. The activity pattern is discussed with reference to the number, the charge and the location of the charge-balancing ions. The active centres are considered to be protons in the supercages, with the cations of catalysts containing high percentages of divalent ions exerting an indirect specific effect through the reaction: [formula ommitted].It is concluded that at low percentage exchange, Ca2+ ions remain exclusively in internal sites during the catalysis. © 1969, Walter de Gruyter. Alle Rechte vorbehalten.