Template-free fabrication of nitrogen-doped mesoporous carbon catalysts with high water resistance for selective catalytic oxidation of H2S

Abstract

Nitrogen-doped carbon-based catalysts have been widely utilized in the selective catalytic oxidation of hydrogen sulfide, but there are some challenges in practical applications, such as the stability and water resistance of the catalysts. This study has synthesized a series of metal-free nitrogen-doped mesoporous carbon (CN-x-T) catalysts with a large specific surface area, high N content, and many defects for the selective catalytic oxidation of H₂S by polymerization strategy and pyrolysis without templates. The nitrogen basic sites of CN-x-T facilitate the dissociation of H₂S and the activation of O₂, while the mesoporous structure enables efficient mass transfer within and outside the catalyst. The prepared NC-4-800 catalyst exhibits excellent catalytic performance, achieving a conversion of 100 % and a sulfur selectivity of 85 % at 150 °C. Furthermore, the catalyst demonstrates excellent stability and water where the catalysts show remarkable stability over 150 h. The activity could remain stable even when 50 % water was introduced into the system.