Advanced theoretical insights into energetically favorable and structurally stable boron-doped graphitic carbon nitride for effective catalytic removal of nitrous oxide and carbon monoxide from industrial flue gases.

Abstract

In this study, density functional theory (DFT) calculations are employed to evaluate the applicability of a boron-doped graphitic carbon nitride (B@g-C₃N₄) nanosheet for the reduction of nitrous oxide (N₂O) and carbon monoxide (CO). From the results, it is clear that the B-doping of graphitic carbon nitride is favorable energetically, and the resulting B@g-C₃N₄ is both physically and thermodynamically stable. Nitrous oxide molecule spontaneously dissociates upon interaction with the B@g-C₃N₄ surface from its oxygen side without requiring an external supply of energy, releasing -2.54 eV of energy. The adsorption energy of N₂O on the B@g-C₃N₄ is more negative than that of CO implying that N₂O will predominately occupy the catalyst surface in the presence of CO. The subsequent CO + Oad reaction efficiently removes the oxygen atom which is covalently bonded with the active side of the B@g-C₃N₄ surface, proceeding with a minimal energy barrier of 0.05 eV significantly lower than previously reported catalysts. Stability tests reveal that the catalytic activity of B@g-C₃N₄ remains unaffected in the presence of H₂O and O₂ species. These findings suggest that B@g-C₃N₄ is a promising and efficient catalyst for the removal of N₂O and CO from flue gases.