A sol-gel route for the synthesis of Bi2Ru2O7 pyrochlore oxide for oxygen reaction in alkaline medium

In this investigation, Bi2Ru2O7 pyrochlore-type oxide was prepared using the Pechini process. We employed a sol-gel route, in which a solution of Ru(III) and BI(III) in a mixture of citric acid and ethylene glycol was heated to form a polymeric precursor, followed by an annealing at higher temperatures during various periods. The oxide obtained was identified by X-ray diffraction analysis. The results revealed that the formation of homogeneous oxide with a single pyrochlore structure phase occured at or above 650 degreesC. Sample powders consisted of fine grains with homogeneous morphology and an average size of about 0.5 mum. This new preparation procedure yielded an electrode material with improved electrochemical activity compared to those elaborated through conventional methods. (C) 2001 Academic Press.