Construction of Fe2O3 loaded and mesopore confined thin-layer titania catalyst for efficient NH3-SCR of NOx with enhanced H2O/SO2 tolerance

TiO2 is a famous support for selective catalytic reduction of NO with NH3 (NH3-SCR). Engineering the morphology and structure of TiO2 is effective to modulate the interaction with surface dispersed component, providing further opportunity to improve catalytic performance. In this study, we rationally construct thin-layered titania confined in mesoporous silica via a surface grafting strategy. It exhibits high specific surface area with amorphous structure along mesopore channel, and much more Bronsted acid sites are generated than bulk TiO2 due to defect induced oxygen-related species. After iron oxide loading, both the denitration activity and H2O/SO2 tolerance are greatly promoted as compared to conventional Fe/TiO2. Further characterizations reveal the obtained catalyst displays uniform iron oxide dispersion and intense Fe-Ti interaction, resulting in superior redox behavior and increased acidity. Notably, it is found the introduction of H2O exhibits a promotional effect on NO conversion efficiency, which can be ascribed to enhancement of NH3 adsorption capability. Besides, SO2 has negligible disturbance on NO/NH3 adsorption, leading to superior sulfur tolerance. The result of present study demonstrates vital role of surface structure engineering of TiO2 for sustainable denitration, which opens up a new avenue for designing well-performed and stable NH3-SCR catalysts.

Automated summary

Engineering the surface structure of TiO2 can enhance catalytic performance and stability, as well as improve the activity of NH3 selective catalytic reduction for denitration.