Ti doping-induced strain engineering boosts low-temperature NH3-SCR deNOx performance and H2O/SO2 resistance of Ce8MnOx.

H2O and SO2 poisoning of cerium-manganese oxide catalysts remains a critical challenge for low-temperature selective catalytic reduction of nitrogen oxides by NH3. Here we show that Ti doping of CeO2 induces lattice contraction and structural distortion, promoting the generation of oxygen vacancies, active oxygen species, and stable Ce-O-Ti interfaces. These strain-engineered structural modifications enhances surface Lewis acidity and triggers a downshift of the d-band center, collectively improving low-temperature catalytic activity and resistance to H2O/SO2 poisoning. The optimized Ce8MnTi2.5Ox catalyst achieves over 90% nitrogen oxides removal across a 150-335 °C temperature range. Under 5 vol.% water and 100 ppm SO2, it maintains over 98% efficiency for 12 h at 210 °C. Furthermore, during stepwise heating from 150 °C to 240 °C with 5 vol.% H2O and 200 ppm SO2, initial activity suppression below 180 °C is fully reversed at or above 210 °C, demonstrating temperature-driven regeneration. This study introduces a strain-engineering strategy for designing robust catalysts for low-temperature nitrogen oxides removal.