Ceria accelerates ammonium bisulfate decomposition for improved SO2 resistance on a V2O5-WO3/TiO2 catalyst in low-temperature NH3-SCR

Background: Ammonia bisulfate (ABS) deposition on the active sites of the catalyst surface is the main reason for SO2 poisoning in low-temperature NH3-selective catalytic reduction (SCR). Accelerated ABS decomposition efficiently enhances the SO2 resistance. Methods: In this work, ceria was specifically chosen to decorate V2O5-WO3/TiO2 catalyst (Ce-VW/Ti) to activate ABS decomposition in low-temperature NH3-SCR. Significant findings: The optimal 7Ce-VW/Ti catalyst accelerated the decomposition of ABS and had superior SO2 tolerance at 250 degrees C. The additive CeO2 improved the specific surface area and surface acidity, favoring the NH3- SCR catalytic activity. ABS was preferentially deposited on the additive CeO2 on the surface of the 7Ce-VW/Ti catalyst and generated cerium sulfate, eventually protecting the active V2O5 sites and TiO2 support. Moreover, high quantity of V5+ and charge transfer between active species V2O5 and support TiO2 could be maintained due to CeO2 protection, subsequently maintaining the high NH3-SCR performance and enhancing the SO2 tolerance.

Automated summary

In this study, ceria was used to decorate a catalyst to enhance the decomposition of ammonia bisulfate in low-temperature NH3-selective catalytic reduction. The optimal catalyst showed accelerated ABS decomposition and superior SO2 tolerance at 250 degrees Celsius. The additive CeO2 improved the catalyst's specific surface area and acidity, favoring the catalytic activity.