Enhanced alkali resistance of CeO2/SO42 −–ZrO2 catalyst in selective catalytic reduction of NOx by ammonia

• Ceria supported on sulfated zirconia has a remarkable resistance to alkali poisons.
• Sulfation treatment of supports greatly enhances the surface acidity.
• Adequate acidity leads to higher SCR activity and resistance to potassium poisons.
• Introduced potassium could result in a higher surface area of catalysts.

Ceria catalysts supported on sulfated zirconia showed a remarkable resistance towards alkali metal poisoning in selective catalytic reduction of NO by NH3. TPD results revealed sulfation treatment of supports produced massive acid sites on the surface of catalysts. Adequate acidity was of importance for the enhanced resistance to alkali metal ions. The introduction of potassium did not affect the crystalline phases and morphology of catalysts, but it could lead to higher surface areas of samples.