Selective Oxidation of H ₂ S via P and Transition‐Metal Dual Sites on Polymeric Carbon Nitride

The development of catalysts featuring high-density active sites and superior stability is critical for achieving efficient and selective H₂S oxidation. This study systematically investigates the catalytic performance and reaction mechanisms of transition metal-embedded phosphorus-doped carbon nitride catalysts (i.e., TM-P@melon, TM = Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, and Zn) for H₂S oxidation using density functional theory calculations. Our calculations identified FeN₄-P@melon and MnN₄-P@melon as the most promising candidates, with Gibbs free energy changes (ΔG) of -0.24 eV and 0.07 eV for the potential-determining step in the selective oxidation of H₂S to elemental sulfur, respectively. Anchored TM and P atoms act synergistically to narrow the melon-CN band gap and enhance O₂ adsorption/activation, thereby boosting the catalytic reaction. This work provides fundamental theoretical insights for designing highly efficient and selective H₂S oxidation catalysts while elucidating the atomic-level mechanisms governing the catalytic process.