Performance impact and poisoning mechanism of arsenic over commercial V2O5–WO3/TiO2 SCR catalyst

• As2O3 was adsorbed on commercial V2O5–WO3/TiO2 catalysts by heating arsenic ore to generate arsenic-containing flue gas.
• Commercial V2O5–WO3/TiO2 SCR catalyst was deactivated seriously with adsorption of arsenic.
• As2O3 was oxidized to As2O5 to result in the catalytic deactivation by forming dense coverage.
• The arsenic-poisoning mechanism model of commercial V2O5–WO3/TiO2 SCR catalyst was proposed.

The performance impact and poisoning mechanism of arsenic on commercial V2O5–WO3/TiO2 SCR catalysts were studied. XRD, BET, FT-IR and XPS were used to characterize its physical–chemical properties. The results showed that As2O3 would be adsorbed on the catalyst surface and most oxidized by surface chemisorption oxygen to ultimately form As2O5. Lattice oxygen of V2O5 may also be transformed into surface sorption oxygen to oxidize As2O3, but tungsten and titanium species showed no changes in this progress. The creating As2O5 formed dense layer on catalyst surface, preventing NH3 adsorption and active sites recovery, which finally resulted in catalytic deactivation.

Figure optionsDownload as PowerPoint slide