First-principles investigation of an efficient non-noble single-atom catalyst Fe1/Ti2CO2 for formaldehyde oxidation

Indoor formaldehyde (HCHO) removal holds paramount significance for human health, particularly in mild conditions. Here, we introduce a new non-noble single-atom catalyst, Fe₁/Ti₂CO₂, designed for formaldehyde oxidation. The oxidation mechanism of HCHO on Fe₁/Ti₂CO₂ was studied by density functional theory. The HCHO oxidation mechanisms of the Langmuir–Hinshelwood (LH) mechanism and the Eley–Rideal (ER) mechanism were explored. The activation energies of all possible intermediates and their elementary steps in the reaction were given. Through thermodynamic and kinetic analysis, reaction rates at different temperatures ranging from 300 K to 600 K were obtained. In the temperature range studied, the reaction of formaldehyde oxidation can occur spontaneously and irreversibly. The minimum activation energy is only 0.73 eV, and the dissociation of CO₂ and H₂O is endothermic, with an energy of 1.30 eV. This indicates promising practical applications for the catalyst. Our work can assist in designing new catalysts for formaldehyde oxidation under mild conditions.