Dual improvement in acid and redox properties of the FeOx/OAC catalyst via APS oxygen-functionalization: High low-temperature NH3-SCR activity, SO2 and H2O tolerance

Abstract

Carbon-based transition metal catalysts (CTCs) have shown tremendous potential within NOx abatement, while the improvement of low-temperature NH3-SCR activity and SO2 and H2O tolerance remains challenging. Herein, we report an easily-achievable strategy to regulate the active phases of the FeOx/AC catalyst via APS oxygen-functionalization for improving in acid and redox properties and facilitating NH3-SCR activity. For redox sites, APS oxygen-functionalization boosted the metal-support interaction, immobilized γ-Fe2O3 nanoparticles highly dispersed on FeOx/OAC1.5-60-3 surface. Meanwhile, Fe valence and oxygen vacancy of FeOx were tailored by APS oxygen-functionalization, resulting in the formation of active oxygen vacancy-coupled Fe2+. For acid sites, in situ DRIFTs further confirmed that APS oxygen-functionalization enhanced the adsorption and activation properties of NH3 over the oxygen-containing functional groups (OCFGs) on FeOx/OAC1.5-60-3. Due to the improvement of acid and redox properties, FeOx/OAC1.5-60-3 delivered superior NO conversion (>90 %) at 120–250 °C and SO2/H2O resistance in comparison with FeOx/AC. Therefore, this work sheds light on a robust and pragmatic strategy for the rational design of CTCs and provides a new insight in improving catalytic performance of CTCs.