Overcoating the Surface of Fe-Based Catalyst with ZnO and Nitrogen-Doped Carbon toward High Selectivity of Light Olefins in CO2 Hydrogenation

ZnO and nitrogen-doped carbon (NC) overcoated Fe-based catalysts (Fe@NC) were synthesized and evaluated in CO2 hydrogenation reaction. The Fe@NC exhibited enhanced catalytic activity, stability, and high selectivity toward light olefins and C5+ hydrocarbons. The olefins over paraffins ratio in the range of C2–C4 increased 24 times from 0.07 to 1.68 compared with the benchmark Fe3O4 catalyst. The evolution of iron species was observed during the hydrogenation reaction. The inactive θ-Fe3C phase disappeared, and the active phases for CO2 hydrogenation, Fe3O4 and Fe5C2, formed during the hydrogenation reaction. Overcoating the surface of Fe-based catalysts can be used as a useful strategy to modulate the product selectivity toward sustainable production of value-added hydrocarbons from CO2.