Optimizing Selective Catalytic Reduction of NO with NH 3 on Fe 2 O 3 /WO 3 via Redox‐Acid Synergy

An iron‐tungsten oxide catalyst was developed for selective catalytic reduction of NO with NH 3 (NH 3 ‐SCR) by supporting Fe 2 O 3 nanoparticles onto hexagonal WO 3 nanorods. The Fe 2 O 3 /WO 3 catalyst showed much higher catalytic activity than Fe 2 O 3 and WO 3 , as explained by the synergistic effects caused by acid sites (provided by WO 3 ) and redox sites (provided by Fe 2 O 3 ). X‐ray diffraction and transmission electron microscopy techniques revealed that the crystal structures and morphologies of Fe 2 O 3 and WO 3 kept unchanged during the preparation of Fe 2 O 3 /WO 3 . NH 3 adsorption curves, NH 3 temperature programmed desorption, and temperature programmed surface reaction of NO demonstrated that WO 3 possessed strong acidity but poor redox ability, whereas Fe 2 O 3 had high redox ability but inadequate acidic property. Therefore, the enhancement in catalytic activity (when using Fe 2 O 3 /WO 3 as a catalyst) should originate from the redox‐acid synergy, as further evidenced by the low SCR activity of pure Fe 2 O 3 and Fe 2 O 3 /TiO 2 with low capacity for adsorbing NH 3 . In addition, Fe 2 O 3 /WO 3 showed high activity and stability in the presence of K + , SO 2 , and H 2 O, demonstrating its potential in practical applications.