CCl4-enhanced isomerization of butene over decationated Y zeolites

Abstract

The catalytic activity of decationated Y zeolite for the isomerization of cis-but-2-ene at 298 K was enhanced by CCl₄ when the zeolite had been degassed at high temperatures (> 773 K). A radical mechanism has been proposed for the CCl₄-enhanced isomerization. Considerable formation of a partially charged 2-butyl radical was observed in the butene + CCl₄ system on the zeolite pretreated at 923 K. The radical was assumed to be a reaction intermediate. The generation of the radical may be promoted by CCl₃ radicals or by chlorine atoms formed through the decomposition of CCl₄ on dehydroxylated sites in the zeolite.