Promotion of Phosphorus on Carbon Supports for MnOx−CeO2 Catalysts in Low‐Temperature NH3−SCR with Enhanced SO2 Resistance

Abstract

AbstractMnOx−CeO2/P‐CA catalysts were prepared via incipient wetness impregnation of Mn(NO3)2 ⋅ 4H2O and Ce(NO3)3 ⋅ 6H2O over phosphorus‐doped carbon aerogels (P‐CA) for selective catalytic reduction of NO by NH3 (NH3−SCR). The results show that P doping on carbon support significantly promotes the NH3−SCR performance of MnOx−CeO2/P‐CA catalysts. P modification can improve the hydrophilicity of carbon support and facilitate the dispersion of MnOx−CeO2 components on carbon surface, which enhances the electronic interactions between MnOx and CeO2. The optimal catalyst 10 %MnOx−CeO2/P‐CA shows higher surface acidity, more Mn4+ and Ce3+, and a larger amount of surface chemisorbed oxygen (Oα) than that of 10 %MnOx−CeO2/CA catalyst. As a result, even though in the company of SO2, more NO can be adsorbed and oxidized over the 10 %MnOx−CeO2/P‐CA catalyst to generate more NO complexes, alleviating the suppression of SO2 on the SCR reaction via Langmuir‐Hinshelwood (L−H) mechanism, and thus the SO2 resistance is enhanced.