Chemical Physics Impact (Jun 2023)
The different effect of SO2 on Zn-poisoned commercial V2O5-WO3/TiO2 catalysts with varied Zn loading
Abstract
Commercial V2O5-WO3/TiO2 (VWTi) catalysts used in NH3-SCR reaction with varied Zn loading were prepared and then effect of SO2 on Zn-poisoned VWTi catalysts was investigated. Zn could cause the deactivation of VWTi catalysts. Nevertheless, the effect of SO2 on Zn-poisoned VWTi catalysts varied with Zn loading. For Zn-poisoned catalyst with low content of Zn (1.0 wt.%, ZnL), SO2 would promote the activity recovery of the catalyst. However, SO2 had no influence on the Zn-poisoned catalyst with high Zn content (4.0 wt.%, ZnH). The catalyst was characterized by N2 adsorption-desorption, XRD, XPS, SO2-TPD, NH3-TPD, H2-TPR and in situ DRIFTS. Tri-coordinated sulfate species were formed on ZnL sample in the presence of SO2, and the sulfate species could form new Brønsted acid sites, causing the recovery of activity. But ZnSO4 was appeared and no Brønsted acid sites formed on ZnH sample under SO2, thus the activity of ZnH sample changed little.