The Excellent Anti-K Ability of CeSbTi Oxide Catalysts for Selective Catalytic Reduction of NO with NH3

A novel K-resistant CeSbTi mixed oxide catalyst was prepared by co-precipitation method for ammonia selective catalytic reduction (NH3-SCR) of NOx. The experimental results show that the introduction of Sb2O5 can significantly improve the catalytic activity of the CeTi catalyst. The modulated CeSbTi catalyst has good resistance to K, and the NOx conversion rate was as high as 95% after K poisoning. Its superior catalytic activity could be ascribed to the large specific surface area with increased acid sites and more oxygen defects and Ce3+ species after the introduction of Sb2O5, which prompt NH3 adsorption and activation. In addition, NH3-SCR reaction over CeSbTi and K/CeSbTi catalysts follows the E-R mechanism. The introduced Sb-O bond as the base capture site preferentially binds to potassium and releases part of the active Ce sites, thus retaining more acid sites and oxygen defects to a certain extent.