硫酸化钛铈氧化物催化剂的抗重金属中毒

The development of highly stable purification catalysts for nitrogen oxides in industrial flue gas is an important requirement for achieving ultra-low emissions of flue gas. At present, the most widely used SCR commercial V₂O₅-WO₃/TiO₂ catalyst in industry often faces the problem of heavy metal poisoning deactivation. This paper developed sulfated-titanium-cerium-oxide catalyst with excellent resistance to heavy metal (Pb, Zn, Cd) poisoning by using impregnation method to modify CeO₂ carrier. The NO conversion of Pb, Zn, and Cd poisoned sulfated-titanium-cerium-oxide catalysts were 75%, 73%, and 63%, which were 28%, 36%, and 43% higher than those of Pb, Zn, and Cd poisoned V₂O₅-WO₃/TiO₂ catalysts at 300 ℃ under the gas hourly space velocity (GHSV) of 360 000 h^-1. The Raman results showed that the sulfated-titanium-cerium-oxide catalyst maintained a high concentration of oxygen vacancies even after Pb poisoning. The XPS and H₂-TPR results showed that Pb interacts with SO₄^2-, protecting the Ce active sites on the catalyst surface, thereby inhibiting the influence of Pb on denitrification activity. The NH₃-TPD results showed that the doping of SO₄^2- can significantly increase the surface acidity of the catalyst, and the surface acidity of the catalyst remains unchanged after Pb poisoning, thus exhibiting high and stable denitrification activity. This study can provide a new way for the design of heavy metal poison-resistant SCR catalysts.