Fig. 4: Mechanistic investigation of CO₂ conversion on LaFeO₃.

Temperature-dependent in situ DRIFTS spectra over (a) LaFeO₃ and (b) LaFeO₃ + H-ZSM-5. c Free energy diagrams of CO₂ hydrogenation on the surface of the LaFeO₃ (220) surface with O_v, showing carboxyl (red) and formate (blue) pathways toward formaldehyde and the formaldehyde hydrogenation pathway (orange) to produce CH₄. To indicate the effect of molecular desorption, the states of gas-phase molecules are highlighted as bold horizontal lines. The competition between molecule desorption and further hydrogenation could be elucidated in the cases where gaseous HCOOH and H₂CO are assumed to be reactants for subsequent hydrogenation. d TS, transition states structure over LaFeO₃ during CO₂ to CH₄. Spheres in black, red, brown, and green represent C, O, Fe, and La atoms, respectively.