Heavy metal poisoning resistance of sulfate-titanium-cerium-oxide catalyst
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 SO42,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 SO42-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.
国家科技期刊平台
NSTL
万方数据
