Mechanochemical incorporation of magnesium in iron-based composite surface for efficient hydrogenation of carbon dioxide to light olefin

Catalytic hydrogenation of CO2 to light olefin (C2= - C4=) not only reduces greenhouse gas emissions but also utilizes CO2 efficiently. A highly active and selective iron-based composite from facile high-energy mechanochemical ball milling was developed for CO2 hydrogenation to C2= - C4=. Under a condition of 320 ℃, 1.0 MPa and 9600 mL h−1 gcat-1, a high C2= - C4= selectively of 55.4 % in hydrocarbons at CO2 conversion of 32.1 % is achieved, outperforming the previous reports under similar reaction condition. An “O-Fe/Mg-O” structure formed by incorporating of Mg into Fe3O4 surface during high-energy mechanochemical ball milling contributes to the efficient adsorption and activation of CO2 to CO. The sustainable CC coupling of CO with surface carbon on K2O-adsorbed Fe5C2 surface promotes the C2= - C4= production. This work provides a new strategy for developing highly efficient catalyst for CO2 conversion to value-added chemicals.