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 (NH 3 -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 (V 2 O 5 ) 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 NO 2 with ammonia from ammonium bicarbonate, (NH 4 )HCO 3 . (NH 4 )HCO 3 was pre-mixed with the catalyst and packed in a reactor operating at 120°C. Effect of V 2 O 5 on NO 2 conversion was investigated. A gas flow rate of 50cc/min with 250 ppm NO 2 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 V 2 O 5 composition led to the increase in removal of NO 2 . SEM analyses indicate that V 2 O 5 loading up to 5% changed the microstructure of the catalyst to become more structured and porous favoring the reduction of NO and NO 2 .