Poisoning Effects of P and Zn on Commercial NH3-SCR V2O5-MoO3/TiO2 Catalyst

The purpose of this study is to investigate the poisoning effects of Phosphorus (P) and Zinc (Z) over commercial NH
₃
-SCR V
₂
O
₅
-MoO
₃
/TiO
₂
with realistic concentrations, used in coal-fired power plant. The catalyst is poisoned by two different methods, incipient wetness impregnation, and solid diffusion method and then characterized by NH
₃
-Temperature Programmed Desorption (NH
₃
-TPD) and H
₂
-Temperature Programmed Reduction (H
₂
-TPR). The results show that P and Zn had poisoning effects over V
₂
O
₅
-MoO
₃
/TiO
₂
when poisoned by Incipient Wetness Impregnation method, but there are negligible poisoning effects when poisoned by solid diffusion. On the other hand, P has comparatively more poisoning effects as compared to Zn in both poisoning methods. NH
₃
-TPD and H
₂
-TPR tests indicate that the ammonia desorption curves for P and Zn poisoned catalysts using incipient wetness impregnation method are shifted towards lower ammonia desorption, while the vanadium V active component is reduced from V
⁵⁺
to V
⁴⁺
which has been observed to causes the deactivation of the catalyst.