Vanadium catalyst based on a tungsten trioxide structure modified with antimony in NH3-selective catalytic reduction for improved low-temperature activity

For NH3-selective catalytic reduction (SCR) of NO, a catalyst that exhibits effective DeNOx performance and SO2 resistance at low temperatures is necessary. In V2O5-WO3/TiO2 systems, a WO3 structure enhanced by Sb addition is effective in improving the SCR performance and SO2 resistance. In this study, the addition of Sb5+ to the WO3 structure increased NH3 adsorption due to Lewis acid formation. Furthermore, the increased electron density on the catalyst surface resulted in the formation of a higher number of WO, which may serve as active sites for SCR, and improved oxygen mobility at low temperatures. This property subsequently caused an increase in the amount of oxygen used in SCR and improved the re-oxidation capacity in the rate-determining step to enhance the DeNOx performance. Furthermore, the NO2– produced during SCR induced the Fast-SCR reaction in V/WSb2Ti. Therefore, V/WSb2Ti produced more N2 than that produced by V/WTi during SCR over a short time, as established using Fourier transform infrared spectroscopy and quadrupole mass spectrometer.