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

The performance impact and poisoning mechanism of arsenic on commercial V 2 O 5 –WO 3 /TiO 2 SCR catalysts were studied. XRD, BET, FT-IR and XPS were used to characterize its physical–chemical properties. The results showed that As 2 O 3 would be adsorbed on the catalyst surface and most oxidized by surface chemisorption oxygen to ultimately form As 2 O 5 . Lattice oxygen of V 2 O 5 may also be transformed into surface sorption oxygen to oxidize As 2 O 3 , but tungsten and titanium species showed no changes in this progress. The creating As 2 O 5 formed dense layer on catalyst surface, preventing NH 3 adsorption and active sites recovery, which finally resulted in catalytic deactivation. [ABSTRACT FROM AUTHOR]