Metathesis of propylene and transformation of ethylene and 2-butenes over a reduced molybdena—alumina catalyst treated with hydrogen

Abstract

The metathesis of propylene, the oligomerization and dimerization of ethylene and the isomerization of cis-2-butene were investigated under identical conditions over a MoO 3/Al 2O 3 catalyst reduced with hydrogen. The hydrogen adsorbed in the course of reduction on the catalyst was: (a) removed by evacuation at 550 °C; (b) left over the catalyst; and (c) removed by evacuation at 550 °C and readsorbed at 40 °C. The rate of ethylene oligomerization is influenced only slightly by the hydrogen adsorbed. Dimerization of ethylene and both cis—trans and double bond shift isomerization of cis-2-butene are accelerated by hydrogen adsorbed both at low and at high temperatures. Propylene metathesis, however, is slightly accelerated by hydrogen adsorbed at low temperature but is greatly suppressed by hydrogen adsorbed at high temperature.