Pd/LaxSr1-xFeO3 perovskite nanocatalysts for selective catalytic reduction of NOx by hydrogen


Catalysis and Nanostructured Materials Laboratory, School of Chemical Engineering, College of Engineering, University of Tehran, Tehran, Iran


In this study, LaxSr1-xFeO3 (x = 0, 0.8) perovskite-type catalysts were prepared by gel combustion method and then 1.0 wt% palladium was loaded on them by a dry impregnation. The catalysts were characterized by XRD, SEM, H2-TPR, O2-TPD, NO-TPD and BET surface area techniques.H2-TPR profiles of the Pd/perovskite catalyst shows the reduction of Pd at around 140˚C which facilitates the reduction of NO in the H2-SCR. TPD results reveal that the substitution of Sr in the perovskites structure remarkably decreases the oxygen mobility and increases the NO adsorption. The H2-SCR of NO on the catalysts was performed in a temperature-programmed reaction apparatus in the presence of oxygen.The effect of carbon monoxide in the feed on H2-SCR was also investigated. The PLSFOcatalyst (1.0 wt% Pd/La0.8Sr0.2FeO3 shows the highest NO conversion and N2 selectivity at a moderate temperature of 190oC.