A Sulfur‐Tolerant MOF‐Based Single‐Atom Fe Catalyst for Efficient Oxidation of NO and Hg⁰

Abstract Catalytic oxidation of NO and Hg⁰ is a crucial step to eliminate multiple pollutants from emissions from coal‐fired power plants. However, traditional catalysts exhibit low catalytic activity and poor sulfur resistance due to low activation ability and poor adsorption selectivity. Herein, a single‐atom Fe decorated N‐doped carbon catalyst (Fe₁‐N₄‐C), with abundant Fe₁‐N₄ sites, based on a Fe‐doped metal–organic framework is developed to oxidize NO and Hg⁰. The results demonstrate that the Fe₁‐N₄‐C has ultrahigh catalytic activity for oxidizing NO and Hg⁰ at low and room temperature. More importantly, Fe₁‐N₄‐C exhibits robust sulfur resistance as it preferably adsorbs reactants over sulfur oxides, which has never been achieved before with traditional catalysts. Furthermore, SO₂ boosts the catalytic oxidation of NO over Fe₁‐N₄‐C through accelerating the circulation of active sites. Density functional theory calculations reveal that the Fe₁‐N₄ active sites result in a low energy barrier and high adsorption selectivity, providing detailed molecular‐level understanding for its excellent catalytic performance. This is the first report on NO and Hg⁰ oxidation over single‐atom catalysts with strong sulfur tolerance. The outcomes demonstrate that single‐atom catalysts are promising candidates for catalytic oxidation of NO and Hg⁰ enabling cleaner coal‐fired power plant operations.