CO₂ Conversion to Higher Hydrocarbons on Iron‐Based Catalysts: Promoter Impact and Kinetic Studies

Abstract Promoted iron catalysts were tested for their Fischer–Tropsch (FT) activity to convert CO 2 /H 2 , CO/H 2 and their mixtures to higher hydrocarbons (220 °C–300 °C, 20 bar, H 2 /(CO 2 +CO) = 3). The results show that iron‐sintered catalysts are able to convert CO 2 at moderate conditions to higher hydrocarbons (HCs) with a still low methane selectivity. Kinetic studies showed that CO 2 is not directly converted to higher HCs but at first reduced by H 2 to CO followed by FTS of CO. For a pure CO 2 /H 2 mixture and a CO 2 conversion of 10% (220 °C), the FeCuZnK catalyst has the highest C 2+ selectivity (57 wt C %), the lowest methane selectivity (10 wt C %), and 32% of CO 2 are converted to the intermediate CO. At 300 °C and a higher CO 2 conversion of 47%, the C 2+ selectivity is even 73 wt C % (methane 19 wt C %, methanol 4 wt C %, and 4 wt C % CO).