Highly efficient NOx reduction with superior H2O and SO2 resistance on Ce-Ti/γ-Fe2O3 dual single-atom Catalysts: Synergistic interactions and mechanistic insights

In this study, a novel strategy was proposed for synthesizing dual single-atom Ce-Ti catalysts supported on gamma-Fe2O3 via ball milling and calcination. Compared to gamma-Fe2O3 and single-atom Ce/gamma-Fe2O3 and Ti/gamma-Fe2O3 catalysts, the Ce-Ti/gamma-Fe2O3 catalyst exhibits superior NO conversion rates and significantly enhanced tolerance to H2O and SO2 at 200-240 degrees C. These advancements are attributed to the synergistic interactions between Ce and Ti, which enhance redox properties, increase Lewis acid site density, and facilitate the Langmuir-Hinshelwood reaction pathway. In-situ DRIFTS and density functional theory (DFT) analyses revealed the mechanistic role of surface-active oxygen species and intermediate formation in promoting the SCR reaction. The findings provide valuable mechanistic insights and establish a scalable approach for the development of high-performance, environmentally friendly catalysts for industrial NOx removal.