Cu-SSZ-13 zeolite–metal oxide hybrid catalysts with enhanced SO2-tolerance in the NH3-SCR of NOx

The relatively low SO2-tolerance of Cu-SSZ-13 zeolite limits its broader applications in NH3-SCR. In this study, Cu-SSZ-13 zeolite-metal oxide hybrids with different metal oxide components (Mn, Co, Ni, Zn) were prepared using the sol-dispersion method. After poisoning with 50 ppm SO2, ZnTi10Ox-Cu-SSZ-13(1:5) catalyst shows a NO conversion of 73 %, which is significantly higher than in Cu-SSZ-13. Regeneration tests together with TGA and SO2-TPD results suggest that ZnTi10Ox in the hybrid catalyst might serve as a sacrificial component that undergoes preferential reaction with SO2, thereby sparing the Cu2+ active sites from sulfur deactivation. ZnTi10Ox-Cu-SSZ-13(1:5) prepared using the sol-dispersion method exhibits higher NO conversion after SO2 poisoning versus mechanically mixed and co-precipitated hybrid catalysts, which may be due to stronger interactions between Cu2+ and the SSZ-13 support. Our results suggest that ZnTi10Ox-Cu-SSZ-13 may be a promising hybrid catalyst for deNOx due to its high reactivity and decreased sensitivity towards SO2.