Preparation and performance of V2O5-CeO2-SiO2 catalyst for the selective catalytic reduction (SCR) of NOx with NH3 at low temperature

Nitrogen oxides (NOx) from flue gas of industry can be removed efficiently by catalytic technology. However, materials development for selective catalytic reduction of NOx with ammonia (NH₃-SCR) is still a challenging task especially at temperature below 200°C. A series of vanadium-ceria oxide supported on mesoporous silica catalyst were prepared by sol gel route with different Vanadia (V₂O₅) contents ranging from 0.2 to 5 w%. These catalysts were studied to see the effect of adding vanadia on the selective catalytic reduction (SCR) of NO₂ with ammonia from ammonium bicarbonate, (NH₄)HCO₃. (NH₄)HCO₃ was pre-mixed with the catalyst and packed in a reactor operating at 120°C. Effect of V₂O₅ on NO₂ conversion was investigated. A gas flow rate of 50cc/min with 250 ppm NO₂ was used. The catalysts were characterized in terms of phase evolution on heat treatment by XRD and microstructure by SEM. Preliminary findings showed that increasing V₂O₅ composition led to the increase in removal of NO₂. SEM analyses indicate that V₂O₅ loading up to 5% changed the microstructure of the catalyst to become more structured and porous favoring the reduction of NO and NO₂.