Study of the isotopic exchange of deuterium with hydrogen in benzene under conditions of its hydrogenation on nickel

Abstract

1. The curves of the temperature dependence of the degree of exchange and hydrogenation of benzene during the simultaneous occurrence of these reactions on a nickel catalyst are of different types. 2. The introduction of a substantial amount of cyclohexane into the initial mixture has no effect upon the degree of hydrogenation of benzene, but it appreciably lowers the degree of exchange at temperatures above 150°. 3. The curves of the isotopic distribution of cyclohexane, formed during the process of hydrogenation (deuteration) of benzene, differ from the curves of the isotopic distribution of the products of exchange both of benzene and of cyclohexane, introduced separately. 4. The observed experimental facts can be explained on the assumption that the reactions of deuterohydrogen exchange and hydrogenation of benzene proceed through different intermediate surface compounds.