抄録
Adsorptive properties of LaY zeolite for some aromatic hydrocarbons and ethylene were investigated by a gas chromatographic method. With the pretreatment temperature of LaY being risen, the retention volume of aromatics increased, whereas that of ethylene decreased. Though the heat of adsorption of benzene slightly increased with the pretreatment temperature, that of ethylene was substantially independent of the thermal treatment of LaY. A linear relationship was found between the decrease in the ionization potential of aromatic hydrocaronbs and the increase in the heat of adsorption.
Catalytic properties of LaY for the alkylation of benzene with ethylene were also investigated by means of a flow system. The pretreatment temperature being increased, the initial rate of alkylation sharply decreased. On the other hand, the apparent activation energy of the reaction was not affected by the thermal treatment of LaY.
From these points of view, it is deduced that ethylene is adsorbed on the Brönsted acid sites of LaY to form the carbonium ion which acts as a reaction intermediate of alkylation. On the other hand, benzene seems to be adsorbed on the Lewis acid sites to form a charge transfer complex.
