CATALYTIC PROPERTIES OF THE YTTRIUM FORM OF TYPE Y ZEOLITE IN THE HYDROGENATION OF PROPYLENE

Abstract

The catalytic properties of type Y zeolite, the initial sodium form and one containing 46% yttrium, were studied by a pulsed micromethod in the hydrogenation of propylene at 200 C. Although the samples manifest catalytic activity after treatment with hydrogen at 200 to 550 C, the activity is unstable. The degree of conversion of propylene and the nature of its drop on the yttrium form depend on the temperature of preliminary treatment with hydrogen (optimum 350 C). After such activation, propylene is 97% hydrogenated. on the basis of a comparison of the activity of the sodium and yttrium forms, it is concluded that the hydrogenating properties are manifested as a result of the introduction of the yttrium cation into the lattice of the zeolite.