Regeneration of sulfur-poisoned CeO2 catalyst for NH3-SCR of NOx

The effects of regeneration on the activities and structure of CeO2 catalysts for NH3-SCR of NOx have been studied in this article. CeO2 catalyst is deactivated by SO2 for NH3-SCR of NOx in a 200h long-term operation at 350°C due to the formation of sulfates, and its NOx conversion decreases from 100% to 83% gradually. However, sulfates can be removed from sulfur-poisoned CeO2 catalysts under high temperature thermal treatment in air. After regeneration, NOx conversion of sulfur-poisoned CeO2 catalyst is recovered to about 100% at 350°C. Moreover, the regeneration temperature is related to the nature of the sulfates formed on the sulfur-poisoned CeO2 catalysts.