Promoting effect of tantalum and antimony additives on deNO x performance of Ce 3 Ta 3 SbO x for NH 3 -SCR reaction and DRIFT studies

Abstract A superior Ce Ta Sb composite oxide catalyst prepared using homogeneous precipitation method exhibited excellent deNO x efficiency and nearly 100% N 2 selectivity with broad operation temperature window and better resistance to higher space velocity, meanwhile strong resistance to H 2 O and SO 2 . This catalyst was systematically characterized using XRD, N 2 adsorption, SEM, TEM, XPS, ESR, Raman, H 2 -TPR, NH 3 -TPD and in situ DRIFTS. There exists a synergistic effect between Ce, Ta and Sb species. It is further indicated that the prominent deNO x performance of the Ce 3 Ta 3 SbO x catalyst is attributed to the elevated Ce 3+ concentrations, abundant active surface oxygen species, as well as surface acidity and reducibility, which is closely linked with the synergistic effect between Ce, Sb and Ta species. Results from DRIFTS reveal that the reaction mechanism of surface-adsorbed NH 3 and NO x species is linked to temperature, the L–H mechanism mainly occurs at low temperature ( 300 °C). Overall, these findings indicate that Ce 3 Ta 3 SbO x is promising for NO x practical abatement.