Effect of H2SO4 pretreatment on alkali-resistance performance of FeZrCeTiO /TNT catalyst for NH3-SCR reaction

• Activity and K-resistance of FZCT/TNT catalyst are enhanced by H 2 SO 4 pretreatment. • H 2 SO 4 pretreatment obviously enhances the surface acidity of FZCT/TNT catalyst. • Adsorption strength of NO x on KFZCT/TNT catalyst is weakened by H 2 SO 4 pretreatment. • H 2 SO 4 pretreatment changes the L-H mechanism of FZCT/TNT catalyst to E-R mechanism. CeTiO x catalyst has attracted extensive attention for its superior activity and N 2 selectivity for NH 3 -SCR reaction. However, it still suffers a lot from the deactivation by alkali metals. Thus, it is vital to develop some novel alkali-resistant CeTiO x catalysts for application. In this work, we loaded FeZrCeTiO x component on TiO 2 nanotube (TNT) support to obtain FeZrCeTiO x /TNT (FZCT/TNT) catalyst, and then simply pretreated it with H 2 SO 4 to obtain H 2 SO 4 -pretreated FeZrCeTiO x /TNT (SFZCT/TNT) catalyst. Besides, the effects of H 2 SO 4 pretreatment on catalytic performance, alkali-resistance as well as physicochemical properties of FZCT/TNT catalyst are comprehensively analyzed. The results manifest that excellent catalytic performance and alkali-resistance (mainly in 350–500 °C) are both achieved by simple H 2 SO 4 pretreatment with only small amounts of active components. This can be mainly attributed to the enhanced acid sites (especially B acid), the prompted adsorption and activation of NH 3 species and the inhibited too strong adsorption strength of NO x species.