Fe2O3 enhanced high-temperature arsenic resistance of CeO2–La2O3/TiO2 catalyst for selective catalytic reduction of NOx with NH3

High-temperature arsenic resistance catalysts of CeLa_0.5Fe_x/Ti (x = 0, 0.1, 0.2, 0.3, 0.4, 0.5) series were prepared and measured under a simulation condition of arsenic poisoning. The as-prepared catalysts were characterized by XRD, SEM, TEM, and XPS. The specific surface area and pore size of the catalysts were measured. At x = 0.2, the catalyst shows the best arsenic resistance and catalytic performance. The active temperature range of the CeLa_0.5Fe_0.2/Ti catalyst is 345–520 °C when the gas hourly space velocity is up to 225 000 mL g⁻¹ h⁻¹. Compared with commercial vanadium-based catalysts, CeLa_0.5Fe_0.2/Ti shows much better catalytic performance. The introduction of Fe will improve the dispersion of CeO₂ and increase the concentration of Ce³⁺ and unsaturated active oxygen on the surface. The NH₃-TPD and H₂-TPR results show that the CeLa_0.5Fe_0.2/Ti catalyst has more acidic sites and more excellent redox performance than CeLa_0.5Fe₀/Ti. The CeLa_0.5Fe_0.2/Ti catalyst might have application prospects in the field of selective catalytic reduction of NO_x with NH₃.

The NO conversion of the CeLa_0.5Fe_0.2/Ti is obviously better than that of the commercial vanadium-based catalyst with regard to arsenic resistance and it has good N₂ selectivity, and good SO₂ resistance.