The adsorption of SO₂ on ReO_x/TiO₂ catalysts was rather weak; thus, ReO_x/TiO₂ catalysts exhibited excellent SO₂ tolerance in the NH₃-SCR reaction.

The cooperation of Fe and Ce on V₂O₅–WO₃/TiO₂ improves the K and Pb resistance by promoting the redox and NO_x adsorption ability.

The poisoning effect of single elements on commercial V₂O₅-WO₃/TiO₂ catalysts has been studied in the past decades. In this study, the combined effects of two multi-element systems (phosphorus-potassium and phosphorus-lead) on V₂O₅-WO₃/TiO₂ catalysts were studied by diverse characterizations. The results show that potassium and lead can result in the deactivation of catalysts to different degrees by reacting with active acid sites and reducing the amount of V⁵⁺. However, phosphorus displays slight negative influence on the NO_x conversion of the catalyst due to the comprehensive effect of reducing V⁵⁺ amount and generating new acid sites. The samples poisoned by phosphorus–potassium and phosphorus–lead have higher NO_x conversion than that by potassium or lead, because doped potassium or lead atoms may react with new acid sites generated by phosphate, which liberates more V–OH on the surface of catalysts and reduces the poisoning effects of potassium or lead on vanadium species and active oxygen species.