抄録
The transformations of o-xylene and toluene on synthetic zeolite-X catalysts containing Ca, Cd, La and Ce cations were investigated in the temperature range of 300 to 550°C. The zeolite catalysts had high activities for both isomerization and disproportionation, which could be treated as the first order reaction. In the latter reaction zeolites showed the period of activation, which was decreased with increase of reaction temperature and with addition of a proton donor, such as hydrogen chloride or water.
The proton donor reversively promoted the catalytic activity of zeolite and enhanced the reaction rate proportionately to the amount of the adsorbate. From these observations, the active sites of the zeolite catalyst are formed by the interaction between the zeoliticc cation and the proton donor.
