The deactivation effect of Na2O and NaCl on CeO2-TiO2 catalysts for selective catalytic reduction of NO with NH3

The effect of Na2O and NaCl on CeO2-TiO2 catalyst for the selective catalytic reduction of NO with NH3 was investigated with BET, XRD, XPS, NH3-TPD, H-2-TPR, in-situ DRIFT and catalytic activity measurements. The results showed that both Na species could deactivate the CeO2-TiO2 catalyst and Na2O had a stronger effect than NaCl. The more serious deactivation by Na2O could be ascribed to smaller surface area, fewer surface Ce3+ and chemical adsorbed oxygen, lower surface acidity, and worse reducibility. The introduction of NaCl and Na2O facilitated the formation of new surface NOx adspecies, but were inactive in NH3-SCR reaction. The adsorption of NH3 were inhibited. The NH3-SCR reaction over the CeO2-TiO2 catalyst was governed by both E-R and L-H mechanisms. The introduction of NaCl and Na2O didn't change the NH3-SCR reaction mechanisms. (C) 2020 Energy Institute. Published by Elsevier Ltd. All rights reserved.