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.