tA series of SCR catalysts of mixed iron–erbium vanadates supported on TiO2–WO3–SiO2were preparedand their reduction, textural, structural and morphological properties characterized by temperature pro-grammed reduction, X-ray powder diffraction, B.E.T. methods and transmission electron microscopy.The influence of Fe/Er ratio in the vanadate as well as the effect of aging conditions on their activity inammonia SCR reaction was investigated. SCR activity at medium/low temperature was found to correlatedirectly with the Fe loading of the catalyst, with supported FeVO4resulting the most active material. Thisbehavior might be correlated with the characteristics of Fe3+O V5+bond and the acidity of the V Omoiety. Supported FeVO4suffers a strong deactivation following thermal aging due to rutile formation inTiO2-based support and consequent collapse of surface area. The effect of Er is that of blocking transfor-mation to rutile, thus enhancing activity after thermal treatment. Mixed composition FexEr1−xVO4withx = 0.5 represents the best compromise between activity and stability and are potential candidates fordeNOxprocess when a higher stability is requested.
Mixed iron–erbium vanadate NH3-SCR catalysts
CASANOVA, Marzia;TROVARELLI, Alessandro
2015-01-01
Abstract
tA series of SCR catalysts of mixed iron–erbium vanadates supported on TiO2–WO3–SiO2were preparedand their reduction, textural, structural and morphological properties characterized by temperature pro-grammed reduction, X-ray powder diffraction, B.E.T. methods and transmission electron microscopy.The influence of Fe/Er ratio in the vanadate as well as the effect of aging conditions on their activity inammonia SCR reaction was investigated. SCR activity at medium/low temperature was found to correlatedirectly with the Fe loading of the catalyst, with supported FeVO4resulting the most active material. Thisbehavior might be correlated with the characteristics of Fe3+O V5+bond and the acidity of the V Omoiety. Supported FeVO4suffers a strong deactivation following thermal aging due to rutile formation inTiO2-based support and consequent collapse of surface area. The effect of Er is that of blocking transfor-mation to rutile, thus enhancing activity after thermal treatment. Mixed composition FexEr1−xVO4withx = 0.5 represents the best compromise between activity and stability and are potential candidates fordeNOxprocess when a higher stability is requested.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
