Oxide electrocatalysts pyrochlores

The data summarized in this paper have established that the oxide pyrochlores under discussion substantially reduce the activation energy overvoltages associated with oxygen electrocatalysis. Specifically, it is found that these catalysts, in aqueous alkaline media near ambient temperature, are superior to any other oxygen evolution catalyst and are equal in performance to the best known oxygen reduction catalysts. As bidirectional oxygen electrocatalysts, they appear to be unmatched. 

There are several physical and chemical characteristics of these oxide pyrochlores which may contribute to their high electrocatalytic activity. The previously described alkaline solution synthesis technique (6,7) provided these materials with surface areas typically ranging from 50 to 200 m /g. Thus, one of the basic requirements for an effective electrocatalyst has been satisfied the electrocatalytic activity is not limited by the unavailability of catalytically active surface sites, as is so often the case with metal and mixed metal oxides. 

As the anion-exchange membrane fuel cell is the alkaline-based system, we can use non-platinum-based catalyst. This is a big advantage to lower the cost of fuel cells. Especially perovskite-type and pyrochlore-type oxides have high performance to oxygen-electrocatalysts which could be applicable to the cathode materials. Some oxides have also bifunctional activities as oxygen electrode catalyst to produce a reversible fuel cell thus, future deployment is expected. While, the big problems are stability of the base... 

---