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.