Performances of manganese oxide‐supported cobalt, nickel, and their combinations of varying compositions have been investigated for CO hydrogenation to lower hydrocarbons using a fixed bed microreactor at atmospheric pressure and temperatures ranging from 525 to 575 K. While Co/MnO was found to exhibit high selectivity to olefins in the C2–C4 range, the total yield of hydrocarbons was low. Addition of nickel to cobalt gave a stable catalyst having improved hydrocarbon yields while still retaining good olefin selectivity. The effect of operating conditions on product distribution was studied. Lower space times and higher temperatures favored olefin selectivity. A comparison of Ni and Co catalysts on various support materials was made. MnO‐supported Co catalyst gave significantly higher olefin/paraffin ratio than that obtained using conventional supports such as SiO2 or Al2O3. It was found that Co/MnO exhibited high water‐gas shift activity, and suppressed hydrogen uptake due to strong metal‐support interaction which favored olefin formation. This can be explained on the basis of competitive adsorption of water and hydrogen on the same surface sites resulting in low hydrogenation activity but improved olefin selectivity.

Copper has been added as a second metal to a nickel‐dispersed‐on‐alumina methanation catalyst. Compared with the nickel catalysts without copper, the initial methanation activity was reduced drastically but the tendency to deactivate with time‐on‐stream was much less. There were also less carbon deposition and less sintering of metal particles with the copper‐added catalysts.

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