Portal de Periódicos da CAPES

Methane combustion on some perovskite-like mixed oxides

1998; Elsevier BV; Volume: 16; Issue: 2 Linguagem: Inglês

10.1016/s0926-3373(97)00065-9

1873-3883

Davide Ferri,

Advancements in Solid Oxide Fuel Cells

Some perovskite-like mixed oxides of general formula La1−xA′xBO3 were prepared by the amorphous citrate method and tested for methane combustion within the 300–600°C temperature range. Substitution at A-site with a bivalent (Eu, Sr) or tetravalent (Ce) metal cation led to a decrease or increase of catalytic activity, respectively. La0.9Ce0.1CoO3 proved to be the most active catalyst, showing complete conversion at 500°C. The nature of the metal cation introduced modifies the oxidation state of cobalt, which leads to the formation of cationic or anionic vacancies. TPD-MS analysis confirmed that the catalytic activity is related to the oxygen storage properties of the catalyst. The substitution at B-site (B=Fe, Co, Ni) allowed to find interesting correlations between catalytic activity and the temperature Tmax of maximum oxygen desorption rate.