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

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.