Characterization of Sr²⁺/La<inf>2</inf>O<inf>3</inf> catalyst modified with different cobalt content

Abstract:

Cobalt oxide content and calcination temperature effects on the Sr2+/La2O3 catalyst structure were studied. The Co/Sr - La catalysts were prepared by successive immersion impregnation and characterized by XRD, FTIR, TGA, surface area (B.E.T.) and TPR. The Sr2+/La2O3 catalysts with low cobalt composition show a strong interaction of Co with the intrinsic La2O3 surface defects probably leading to formation of a brownmillerite superstructure, oxygen deficient (LaCoO3-λ), enriched with Co2+ ions. Cobalt contents higher than 2% gave local or island La1-xSrxCoO3 solid solutions and further cobalt addition favors mixed La - Co perovskite-type oxide and cobalt oxide formation. The mixed La - Co oxide is the predominant product when Sr2+ is present as an additive. Higher calcination temperatures favor the mixed oxide formation in all the Co composition.

Año de publicación:

1998

Keywords:

• Catalyst
• characterization
• Perovskite

Fuente:

scopus

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