Tailoring the catalytic activity and selectivity on CO₂ to C₁ products by the synergistic effect of reactive...

The conversion of CO₂ to CO is one of the crucial pathways in the carbon dioxide reduction reaction (CO₂RR). Iron and nitrogen co-doped carbon matrix (FeN₄) is a promising catalyst for converting CO₂to CO with excellent activity and selectivity. However, the reactive mechanism of CO₂RR on the FeN₄ catalyst is not fully unveiled. For example, it is still evasive that the obtained C₁ product is methanol and/or methane instead of CO in some cases. Herein, DFT calculation is conducted to unravel the effect from both solvent molecules and intermediates as axial groups on the selectivity of C₁ products in CO₂RR using FeN₄ catalyts. Calculation results demonstrate that the FeN₄(H), FeN₄(OH), FeN₄(COOH), and FeN₄(CO) configurations are not only beneficial to the removal of CO, but also effectively suppress the hydrogen evolution reaction, whereas the FeN₄, FeN₄(CO₂) and FeN₄(H₂O) configurations are inclined to produce CH₃OH and/or CH₄. The mechanism studied in this work provides an inspiration of optimizing the selectivity of C₁ products in CO₂RR from the perspective of regulating solvent molecules and intermediates as axial groups on FeN₄.