Effects of the morphology and crystal-plane of TiO2 on NH3-SCR performance and K tolerance of V2O5-WO3/TiO2 catalyst

Abstract

Abstract V2O5-WO3/TiO2 is the commercial NH3-SCR catalyst, the morphology and crystal-plane of its support can influence the denitration performance and K tolerance efficiently. TiO2 nano-rods (TiO2-NRs, mainly exposed the {100} facets) has larger BET surface area than those of TiO2 nano-octahedrons (TiO2-NOs, mainly exposed the {101} facets) and TiO2 nano-truncated octahedrons (TiO2-NTs, mainly exposed the {001} facets). The larger BET surface area was conducive to the dispersion of active species, thereby generating more active sites and enhancing the amount of V5+ ratio. Moreover, there was a stronger interaction between the active species (V2O5 and WO3) and TiO2-NRs support, which led to the increase of chemisorbed oxygen ratio and the improvement of surface acidity and redox ability. Furthermore, NH3-SCR reaction over V2O5-WO3/TiO2-NRs (i.e., VWTi-NRs) catalyst followed by both Langmuir-Hinshelwood (L-H) and Eley-Rideal (E–R) mechanisms. While it only followed by an L-H mechanism over V2O5-WO3/TiO2-NOs (i.e., VWTi-NOs) and V2O5-WO3/TiO2-NTs (i.e., VWTi-NTs) catalysts.