Combustion Synthesis as a Preparation Method of Perovskites with Cerium for Metane Oxidation
The aim of this contribution was to evaluate the synthesis of perovskites containing cerium by the combustion synthesis methodology as well as their catalytic behaviour in the methane combustion. Cerium was introduced partially replacing lanthanum into A position of perovskites with general formula AxA’1-xCoO3. The formation of cubic perovskites was confirmed by XRD. The powder containing only lanthanum and strontium in A sites showed a structure transition to orthorhombic at temperatures above 700 °C. The addition of cerium, instead of strontium, induced a structural stabilisation and only a cubic phase was detected up to 1100 °C. High cerium loadings led to the formation of cerium oxide, revealing its up limit into the structure. All samples showed to be active in methane combustion. The results indicated that over the perovskites loaded with cerium the oxygen adsorbed onto the catalyst surface plays a role in the reaction.
Lucio Salgado and Francisco Ambrozio Filho
M. A. Fraga et al., "Combustion Synthesis as a Preparation Method of Perovskites with Cerium for Metane Oxidation", Materials Science Forum, Vols. 530-531, pp. 696-701, 2006