CO and soot oxidation over macroporous perovskite LaFeO3

Bulk, supported and macroporous perovskite LaFeO3 are synthesized and investigated as catalysts for CO and soot oxidation. The structure and physicochemical properties of LaFeO3 are characterized by XRD patterns, N2 physisorption isotherms, TEM, XPS, O2-TPD and H2-TPR measurements. Pure LaFeO3 with desired textural structures are successfully prepared, and the porous sample exhibits the best activity to both reactions, pointing out the importance of fabrication of porous perovskite for the reactions. By correlating with the catalytic activities and the physicochemical properties, it is inferred that the best activity obtained from the porous LaFeO3 is attributed to its large surface area, rich active lattice oxygen and strong surface reducibility. A decrease in the activity of porous LaFeO3 is observed for both reactions when vapor is added, but the activity is sustainable even the vapor percentage increases up to 13.5%, and moreover, the activity can be recovered after vapor is removed.