2011 Annual Meeting

(449g) Mixed-Metal Oxide Electrocatalysts for Oxygen Evolution

Authors

Ethan L. Demeter - Presenter, Carnegie Mellon University
James R Landon - Presenter, Carnegie Mellon University
John R Kitchin - Presenter, Carnegie Mellon University


The electrochemical oxygen evolution reaction could be an important component of future energy systems. If the reaction can be made efficient and cost-effective, it would enable the utilization of renewable energy for hydrogen production, fuel synthesis and oxygen purification from air. Currently there are high overpotentials associated with the O2 evolution reaction due to large reaction barriers within the complex reaction mechanism.  Metal oxides have been identified as potential catalysts for this reaction, but the best performing materials, RuO2 and IrO2 are expensive, while other cheaper oxides are not active enough to be practical or are unstable in the conventional acid electrolyte.

Under alkaline conditions many base metals, such as Ni, are stable to corrosion making them potential candidates for the oxygen evolution reaction. We have investigated mixed metal oxides based on Ni for the oxygen evolution reaction. Especially for mixed Ni-Fe oxides, we have found the mixed metal oxide has superior activity compared to the parent metal oxides, even though there is no evidence of bulk mixing by x-ray diffraction and EXAFS. These mixed oxide electrocatalysts show improvements in air separation performance in electrochemical membrane reactors. We will present our synthesis approaches, physical and electrochemical characterizations, and work to integrate the electrocatalysts into membrane electrode assemblies for use in applications.