Method for preparing an alumina supported perovskite type oxide composition, alumina supported perovskite type oxide composition and its use

An alumina supported perovskite oxide composition composite comprising the following features:

• i) at least 50 wt. % of a doped alumina;
• and
• ii) between 5 and 50 wt. % of a perovskite oxide of formula:
• ABO3,
• wherein:
• A comprises a rare-earth element, an alkaline earth element, an alkali element, Pb2+, Bi3+ or mixtures thereof and
• B comprises transition metals including mixtures of transition metals;
• and
• ABO3 being characterized by having a crystallite size of less than 5 nm after calcination at 850° C. for 3 hours and having a crystallite size of less than 2 nm after calcination at 700° C. for 4 hours.