Competitive\nCoordination-Induced Formation of Fe-O-Ce\nStructure in Beta Zeolite to Enhance Moderate-to-High Temperature\nSelective Catalytic Reduction of NO<sub>x</sub> with NH<sub>3</sub>

Fe-based catalysts are capable of selective catalytic\nammonia reduction\n(NH<sub>3</sub>-SCR) for NO<sub>x</sub>, while efficient loading of\nactive components and optimization of reactive adsorption models are\nstill required to achieve enhanced catalytic performance. Here, Ce\nand Fe dual-ion doped Ce-Fe-Beta zeolite catalysts were constructed\nvia a facile ion exchange strategy for efficient NH<sub>3</sub>-SCR.\nThe competitively coordinated interaction between Ce and Fe within\nCe-Fe-Beta zeolite induces the transformation of aggregated Fe<sub>2</sub>O<sub>3</sub> species to incorporated Fe species with Fe-O\nand Fe-O-Ce bonds. The formed Fe-O-Ce structure enhances the adsorption\nof NO and reduces the energy barrier of the rate-limiting step (NO\n+ O<sub>2</sub> → NO<sub>2</sub>). The synergy between Ce and\nFe can tune the electronic states of Fe species and makes the NH<sub>3</sub>-SCR reaction follow Langmuir–Hinshelwood and Eley–Rideal\npathways. Thus, a high NO<sub>x</sub> conversion of ≥98% is\nachieved over Ce-Fe-Beta zeolite at 350–580 °C under a\nspace velocity of 200 000 h<sup>–1</sup>.