Effect of Fe2O3 on ZrTiO4 support for NH3-SCR catalytic performance; [Fe2O3 对 ZrTiO4 载体 NH3-SCR 催化性能的影响]

The selective catalytic reduction (SCR) NH3 catalyst is mainly used in industrial production and automobile exhaust cleaning. In this study, a novel α%Fe2O3/ZrTiO4 (α=0, 8, 12, 15) catalyst was prepared by the coprecipitation impregnation method. The results show that the NOx conversion rate of 12%Fe2O3/ZrTiO4 catalyst with the optimal composition is high above 80% at 250−400 °C, close to 100% at 300 °C, and N2 selectivity is high above 90% at 200−450 °C. The redox properties, surface acidity, and Oβ/(Oα + Oβ) ratio of ZrTiO4 catalysts are improved after loading Fe2O3 on the ZrTiO4 surface, which is attributed not only to the porous structure of α%Fe2O3/ZrTiO4 catalyst but also to the synergistic interaction between the active component Fe2O3 and the support ZrTiO4. In addition, in-situ DRIFT reactions show that the NH3-SCR reaction of 12%Fe2O3/ZrTiO4 catalyst follows the Eley-Rideal mechanism. A clear reaction mechanism is conducive to a deeper understanding of the reaction process of NOx conversion during SCR. This work provides a feasible strategy for Fe-based SCR catalysts to replace V-based catalysts in the medium temperature range in the future. © 2023 Science Press. All rights reserved.