Effect of vanadium and tungsten loading order on the denitration performance of F-doped V 2 O 5 -WO 3 /TiO 2 catalysts

F-doped V O -WO /TiO catalyst has been confirmed to have excellent denitration activity at low temperatures. Since the V O -WO /TiO catalyst is a structure-sensitive catalyst, the loading order of V O and WO may affect its denitration performance. In this paper, a series of F-doped V O -WO /TiO catalysts with different V O and WO loading orders were synthesized to investigate the effect of denitration performance at low temperatures. It was found that the loading orders led to significant gaps in denitration performance in the range of 120-240 °C. The results indicated loading WO first better utilized the oxygen vacancies on the TiF carrier promoting the generation of reduced vanadium species. In addition, loading WO first facilitated the dispersion of V O thus enhanced the NH adsorption capacity of VWTiF. In situ DRIFT verified the rapid reaction between NO , nitrate, and nitrite species and adsorbed NH over the VWTiF, confirming that the NH selective catalytic reduction (NH -SCR) reaction over VWTiF at 240 °C proceeded by the Langmuir-Hinshelwood (L-H) mechanism. This research established the constitutive relationship between the loading order of V O and WO and the denitration performance of the F-doped VWTi catalyst providing insights into the catalyst design process.