Effect of Ag addition on the thermal stability and catalytic properties of LaFeO3 perovskite

RIOSECO, F.; RADOVIC, L.; GARCÍA, X.; GORDON, A.; PECCHI, G.
Journal of the Chilean Chemical Society 55 (2010) 2010.

DOI: 10.4067/S0717-97072010000100011

Abstract

The effect of low Ag substitution in LaFeO3 perovskite on the thermal stability and catalytic oxidation of toluene was studied. Perovskites of the type La1-xAgxFeO3 (xAg =0.0, 0.05, 0.10) were prepared by the amorphous citrate method; characterized by nitrogen adsorption, XRD, FTIR, SEM-EDAX, TPR and O2 TPD techniques; and tested for the catalytic combustion of toluene in a flow reactor under excess oxygen. In comparison with the pure perovskite LaFeO3, the partially substituted La1-xAgxFeO3 present a perovskite structure with well-defined crystalline phases and greater reduction ability (attributable to the redox pair Fe+3/Fe+4). Noticeable changes in the α and ß-oxygen contents upon silver substitution were detected. Larger content of α-oxygen in the pure LaFeO3 perovskite is associated with greater catalytic activity. Two important effects upon Ag substitution in a pure LaFeO3 perovskites were observed: i) a greater reduction ability, ii) higher occurrence of oxygen vacancies due to ß-oxygen desorption, which were not active in the studied reaction.

see more

Publication Details

Department:

Year:

Type:

Keywords: