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 NOx, 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% NOx 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.