Fig. 5

NOx removal efficiencies of the synthesized SCR catalysts according to vanadium content measured in the temperature range 150–450 °C a NOx conversion and b N₂ selectivity and N₂O concentration. Reaction conditions: [NOx] = 300 ppm, [NH₃] = 300 ppm, [SO₂] = 0 or 300 ppm, [O₂] = 5%, balance N₂, total flow 500 sccm, and the gas hourly space velocity (GHSV) = 60,000 h⁻¹