Stabilization and activation of zirconium oxide based electrocatalysts as PEFC cathode by re-heat treatment

摘要

Development of non-platinum electrocatalyst for oxygen reduction reaction (ORR) is required for real commercialization of polymer electrolyte fuel cells. We focused on group 4 and 5 transition metal oxides, because they have high chemical stability under acidic atmosphere even in high potential region, and are less expensive than platinum. In this study, in order to develop high durability electrocatalysts, zirconium oxide based electrocatalysts prepared by the oxidation of zirconium oxyphthalocyanine in low oxygen pressure were stabilized by heat treatment in the temperature range from 900 to 1200°C for 1 h under nitrogen atmosphere. These catalysts showed higher durability than before stabilization, especially high potential region. Crystallization of surface deposited carbon and zirconium oxide proceeded by heat treatment, and they would improve the durability of the catalyst.