Boosting DeNOx performance via magnetic enhancement in synergistically-optimized γ-Fe2O3-CuO composite oxides.

[Display omitted] • Co-oxidation synthesis strategy achieves strong synergistic effect of copper-iron complexes. • In situ technology explores the synergistic mechanism and magnetic field enhancement mechanism under reaction conditions. • Magnetic field promotes the adsorption of paramagnetic NO molecules and improves performance. Fe or Cu oxides and their composites are cost-effective yet seldom used in DeNO x because they deactivate easily. Doping/supporting enhances activity but increases synthesis complexity and cost. Here, we present a γ-Fe 2 O 3 -CuO composite oxide with a high synergy created through co-oxidation, which upon magnetization, exhibits further enhanced DeNO x activity. Detailed quasi in-situ XRD and in-situ DRIFTS analyses indicate that in Fe-Cu composite oxides, iron species inhibit the full reduction of Cu2+ to Cu0, while copper counters the formation of inactive α-Fe 2 O 3 , contributing to the γ-Fe 2 O 3 -CuO composite's enhanced stability during reactions. Fascinatingly, pre- and post-magnetization XPS and in-situ DRIFTS analyses demonstrate the magnetic field's role in promoting the chemisorption of both oxygen and NO, thereby enhancing DeNO x efficiency. This research not only achieves the synergistic coupling of copper and iron oxides and sheds light on the deactivation processes of their pure species but also serves as a pioneering exploration of magnetic manipulation in catalyst design, laying a foundation for future technological advancements. [ABSTRACT FROM AUTHOR]