Formation of hydrocarbons from CO + H2 using a cobalt–manganese oxide catalyst. A 13C isotopic study

Abstract

The mechanism of the selective formation of C3 hydrocarbons from CO hydrogenation using a cobalt–manganese oxide catalyst (Co/Mn = 1:1 by mass) is discussed. This catalyst demonstrates high C3 selectivities with correspondingly low C1 and C2 selectivities. Reaction of 13CO–12C2H4–H2 mixtures over the catalyst results in the major C3 product containing 13C112C2, which confirms that C3 hydrocarbons result from reaction of the C1 and C2 species. It is concluded that this mechanistic scheme can be exploited to give very high C3 selectivities. A significant reduction in the formation of CH4 was observed for the C2H4–CO–H2 feed when compared to CO–H2 or C2H4–H2 alone, and the origin of this effect is discussed.