Boosting SO₂-Resistant NO Reduction by Modulating Electronic Interaction of Short-Range Fe-O Coordination over...

SO₂-resistant selective catalytic reduction (SCR) of NO remains a grand challenge for eliminating NO generated from stationary combustion processes. Herein, SO₂-resistant NO reduction has been boosted by modulating electronic interaction of short-range Fe-O coordination over Fe₂O₃/TiO₂ catalysts. We report a remarkable SO₂-tolerant Fe₂O₃/TiO₂ catalyst using sulfur-doped TiO₂ as the support. Via an array of spectroscopic and microscopic characterizations and DFT theoretical calculations, the active form of the dopant is demonstrated as SO₄^2- residing at subsurface TiO₆ locations. Sulfur doping exerts strong electronic perturbation to TiO₂, causing a net charge transfer from Fe₂O₃ to TiO₂ via increased short-range Fe-O coordination. This electronic effect simultaneously weakens charge transfer from Fe₂O₃ to SO₂ and enhances that from NO/NH₃ to Fe₂O₃, resulting in a remarkable "killing two birds with one stone" scenario, that is, improving NO/NH₃ adsorption that benefits SCR reaction and inhibiting SO₂ poisoning that benefits catalyst long-term stability.