Establishment of a sustainable energy society has been strong driving force to develop cost-effective and highly active catalysts for energy conversion and storage devices such as metal-air batteries and electrochemical water splitting systems. This is because the oxygen evolution reaction (OER), a vital reaction for the operation, is substantially sluggish even with precious metals-based catalysts. Here, we show for the first time that a hexagonal perovskite, BaNiO3, can be a highly functional catalyst for OER in alkaline media. We demonstrate that the BaNiO3 performs OER activity at least an order of magnitude higher than an IrO2 catalyst. Using integrated density functional theory calculations and experimental validations, we unveil that the underlying mechanism originates from structural transformation from BaNiO3 to BaNi(0.83)O(2.5) (Ba6Ni5O15) over the OER cycling process.

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Low-temperature operation is necessary for next-generation solid oxide fuel cells due to the wide variety of their applications. However, significant increases in the fuel cell losses appear in the low-temperature solid oxide fuel cells, which reduce the cell performance. To overcome this problem, here we report Gd 0.1 Ce 0.9 O 1.95 -based low-temperature solid oxide fuel cells with nanocomposite anode functional layers, thin electrolytes and core/shell fibrestructured Ba 0.5 Sr 0.5 Co 0.8 Fe 0.2 O 3 À d -Gd 0.1 Ce 0.9 O 1.95 cathodes. In particular, the report describes the use of the advanced electrospinning and Pechini process in the preparation of the core/shell-fibre-structured cathodes. The fuel cells show a very high performance of 2 Wcm À 2 at 550°C in hydrogen, and are stable for 300 h even under the high current density of 1 A cm À 2 . Hence, the results suggest that stable and high-performance solid oxide fuel cells at low temperatures can be achieved by modifying the microstructures of solid oxide fuel cell components.

Surfactant bilayers adsorbed on TS-1 zeolite were used as templates to produce colloidal nanocomposites with a polypyrrole (Ppy) shell. The adsorbed surfactant was cetylpyridinium chloride, and it plays a critical role for attaining both the colloidal stability of the nanocomposites and an enhanced conductivity of the Ppy sheath on the TS-1 core. The observed contact conductivity of the nanocomposites was 5 S/cm for a sample with 8 wt % of Ppy incorporation while bulk Ppy powder had a contact conductivity of 0.03 S/cm.