Enhanced SCR Performance of Cu-SSZ-13 via FeNbCe Incorporation: Unveiling the Synergistic Effect on Acidic Site Enrichment and Sulfate Inhibition

To address the limitations of molecular sieves and metal oxides in the NH₃-SCR of NO_x, we synthesized a novel hybrid catalyst by integrating FeNbCe metal oxides with Cu-SSZ-13. The FeNbCe comodification significantly enhanced the low-temperature performance and sulfur resistance of Cu-SSZ-13 while maintaining 100% N₂ selectivity across a broad activity window. The incorporation of Fe, Nb, and Ce reduced weak-acid and Lewis-acid sites while increasing strong Brønsted-acid sites, crucial for catalytic activity. The FeNbCe/Cu-SSZ-13 catalyst exhibited an enhanced surface oxygen content and redox capacity, promoting the “fast SCR” pathway and improving N₂ selectivity at low temperatures. The FeNbCe oxides synergistically reacted with SO₂, protecting Cu²⁺ active sites from sulfur poisoning and maintaining 100% NO_x conversion for 4 h after SO₂ introduction, maintaining 85% within 24 h. In situ DRIFTS characterization confirmed the dominance of the Langmuir-Hinshelwood (L-H) mechanism. The FeNbCe modification represents a significant advancement in the field of NH₃–SCR catalysis, offering a practical and effective solution to enhance the performance of Cu-SSZ-13 while addressing key challenges such as sulfur resistance and low-temperature activity.