Effect of Silver Addition to LaFeO3 Perovskite on the Activity of Monolithic La1-xAgxFeO3 Perovskite Catalysts in Methane Hexane Oxidation

La1-xAgxFeO3 (x=0.05-0.25) perovskites deposited on a honeycomb-shaped monolithic metallic support were used as catalysts for the total oxidation of hydrocarbons. Monolithic catalysts were prepared by washcoating honeycomb substrates with lanthanum-stabilized -Al2O3, on which La1-xAgxFeO3 was deposited. Catalysts with La1-xAgxFeO3 perovskites show higher activity for methane oxidation at x0.05 and hexane oxidation at x0.1 than LaFeO3 catalyst. The perovskite catalysts were characterized by XRD, XPS, SEM, TEM, TPR-H-2, O-2-TPD and BET specific surface area measurement. Ag forms solid solutions with the La1-xAgxFeO3 perovskite lattice for x=0.05-0.1. In La1-xAgxFeO3 perovskites (x0.1), Ag-0 particles with average crystallite sizes from 31 to 41nm were also identified. When Ag is introduced into the LaFeO3 perovskite, both the changes occurring after some Ag is incorporated into its structure and the presence of large crystallites of metallic silver contribute to the catalysts' activity increase. [GRAPHICS] .