PromotingeffectoftantalumandantimonyadditivesondeNOxperformanceofCe3Ta3SbOxforNH3-SCRreactionandDRIFTstudies

A superior Ce-Ta-Sb composite oxide catalyst prepared using homogeneous precipitation method exhibited excellent deNOx efficiency and nearly 100% N2 selectivity with broad operation temperature window and better resistance to higher space velocity, meanwhile strong resistance to H2 O and SO2. This catalyst was systematically characterized using XRD, N2 adsorption, SEM, TEM, XPS, ESR, Raman, H2-TPR,NH3-TPD and in situ DRIFTS. There exists a synergistic effect between Ce, Ta and Sb species. It is further indicated that the prominent deNOx performance of the Ce3 Ta3 SbOx catalyst is attributed to the elevated Ce3+ 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 NH3 and NOx species is linked to temperature,the L-H mechanism mainly occurs at low temperature（<300 ℃）,while the E-R mechanism occurs at high temperature（>300 ℃）. Overall,these findings indicate that Ce3 Ta3 SbOx is promising for NOx practical abatement.