Potassium-modified calcium-ferrate-catalyzed hydrogenation of carbon dioxide to produce light olefins

Hydrogenating CO₂ to produce light olefins is a highly promising route for olefin synthesis. However, the premise of achieving a high yield is to develop a catalyst with a high conversion rate, selectivity, and stability. This paper reports a Ca_2−xK_xFe₂O₅ catalyst with an CO₂ conversion of up to 46%, a light olefin selectivity of 34.59%, and an olefin-alkane molar ratio of 8.31. Ca addition increased the oxygen vacancy concentration and strong basic sites of the catalyst, resulting in improved HCOO* intermediate formation, better CO selectivity, and higher CO₂ conversion rates. Meanwhile, the addition of K further enhanced the rate of CO₂ conversion while also improving the selectivity of light olefins by promoting C–C coupling. Furthermore, the Ca_1.0K_1.0Fe₂O₅ catalyst demonstrated no notable deactivation over a period of 72 h, indicating the strong industrial potential of this catalyst.