Computational investigation of CO2 hydrogenation and electrochemical reduction to formic acid and methanol using chalcogen-doped nitrogen-graphene nanoflake as a metal-free catalyst

Clean fuel production and pollutant removal are critical industrial challenges. This study presents a model for CO₂ adsorption, focusing on non-metallic, biocompatible catalysts. We demonstrate the potential of chalcogen-doped graphene nanoflake modified with pyridinic nitrogen atoms as biocompatible catalysts for hydrogenating CO₂ to formic acid and methanol. Using dispersion-corrected density functional theory, the catalytic hydrogenation and electrochemical reduction of CO₂ over single chalcogen atoms (Se, Te) embedded in nitrogen-doped graphene nanoflake were analyzed. High hybridization between Se/Te and N states near the Fermi level stabilizes the chalcogen atoms on the graphene nanoflake. Se-doped nitrogen-containing graphene nanoflake exhibits lower energy barriers and higher catalytic performance than Te, facilitating CO₂ conversion to formic acid and methanol with improved stability. Migration barriers, electronic structures, and adsorption energies highlight Se-doped nitrogen-containing graphene nanoflake as an efficient catalyst for CO₂ hydrogenation and electrochemical reduction at room temperature. In particular, Se doping not only stabilizes the material but also improves catalytic performance for the selective production of CO/CH₃OH. This work introduces Se-doped nitrogen-containing graphene nanoflake as a promising non-metal biocompatible catalyst.