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 H 2 S 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 H 2 S oxidation using density functional theory calculations. Our calculations identified FeN 4 ‐P@melon and MnN 4 ‐P@melon as the most promising candidates, with Gibbs free energy changes (Δ G ) of −0.24 eV and 0.07 eV for the potential‐determining step in the selective oxidation of H 2 S to elemental sulfur, respectively. Anchored TM and P atoms act synergistically to narrow the melon‐CN band gap and enhance O 2 adsorption/activation, thereby boosting the catalytic reaction. This work provides fundamental theoretical insights for designing highly efficient and selective H 2 S oxidation catalysts while elucidating the atomic‐level mechanisms governing the catalytic process.