Functional carbon materials with Lewis pairs for efficiently transforming sulfur compounds from waste to chemical

As significant supplements to metal-based catalysts, carbon-based catalysts have rarely been applied in selective catalytic oxidation of hydrogen sulfide (H₂S-SCO) at 200–300 ℃ due to inevitable generation of abundant sulfur dioxide (SO₂). Due to the ability to activate and utilize SO₂, the development of Lewis pairs (LPs) into carbon catalysts could be a feasible strategy to alleviate the above issue and realize desired performance but remains challenges. Herein, we propose an affinity-mildness strategy to prepare nitrogen and phosphorus codoped carbon (P-NDC) catalysts under mild conditions, and further reveal the key factors for universal synthesis of such advanced functional carbon materials. The electron-deficient P atom in the carbon matrix as Lewis acid and the electron-rich N atom of pyridinic N as Lewis base comprise LPs, which promote the chemisorption of SO₂ and H₂S, respectively. Benefiting from this improvement, P-NDC strengthens the Claus reaction obeying Langmuir-Hinshelwood mechanism and exhibits a higher sulfur selectivity (96.1 %) than the carbon catalyst without LPs (78.8 %) during H₂S-SCO process at 260 ℃, exceeding reported metal-based and metal-free-based catalysts. This work exemplifies the potential of functional carbon materials with LPs in waste-to-chemical fields, another step towards the optimization vision of carbon materials. Copyright © 2025 Published by Elsevier B.V.