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A Perovskite Oxide Optimized for Oxygen Evolution Catalysis from Molecular Orbital Principles

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Science  27 Oct 2011:
1212858
DOI: 10.1126/science.1212858

Abstract

The slow kinetics of the oxygen evolution reaction (OER) limit the efficiency of many energy storage technologies, such as hydrogen production from water-splitting and rechargeable metal-air batteries. We demonstrate that Ba0.5Sr0.5Co0.8Fe0.2O3–δ (BSCF) catalyzes the OER with intrinsic activity that is at least an order of magnitude higher than the state-of-the-art iridium oxide catalyst in alkaline media. The high activity of BSCF was predicted from a design principle established by systematic examination of more than 10 transition-metal oxides, which showed that the intrinsic OER activity exhibits a volcano-shaped dependence on the eg occupancy of surface transition-metal cations in an oxide. The peak OER activity was predicted to be at an eg occupancy close to unity with high covalency of transition-metal-oxygen bonds.