17 July 2017

Nanomaterial helps store solar energy: efficiently and inexpensively

The growing need to store increasing amounts of renewable energy has recently triggered substantial R&D efforts towards efficient and stable water electrolysis technologies. The oxygen evolution reaction (OER) occurring at the electrolyser anode is central to the development of a clean, reliable and emission-free hydrogen economy. The development of robust and highly active anode materials for OER is therefore a great challenge and has been the main focus of research. Among potential candidates, perovskites have emerged as promising OER electrocatalysts. In this study, by combining a scalable cutting-edge synthesis method with time-resolved X-ray absorption spectroscopy measurements, we were able to capture the dynamic local electronic and geometric structure during realistic operando conditions for highly active OER perovskite nanocatalysts. Ba0.5Sr0.5Co0.8Fe0.2O3−δ as nano-powder displays unique features that allow a dynamic self-reconstruction of the material’s surface during OER, that is, the growth of a self-assembled metal oxy(hydroxide) active layer. Therefore, besides showing outstanding performance at both the laboratory and industrial scale, we provide a fundamental understanding of the operando OER mechanism for highly active perovskite catalysts. This understanding significantly differs from design principles based on ex situ characterization techniques.
Additional information
5232 — Das Magazin des Paul Scherrer Instituts 02/2017
Dr Maarten Nachtegaal
SuperXAS beamline
Laboratory for Synchrotron Radiation and Femtochemistry (LSF)
Swiss Light Source, Paul Scherrer Intitute
5232 Villigen-PSI, Switzerland
Telephone: +41 56 310 30 56
E-mail: marten.nachtegaal@psi.ch
Original Publication
*Dynamic Surface Self-Reconstruction is the Key of Highly Active Perovskite Nano-Electrocatalysts for Water Splitting *
Emiliana Fabbri, Maarten Nachtegaal, Tobias Binniger, Xi Cheng, Bae-Jung Kim, Julien Durst, Francesco Bozza, Thomas J. Graule, Robin Schäublin, Luke H. Wiles, Morgan Petroso, Nemanja Danilovic, Katherine Ayers, Thomas J Schmidt
Nature Materials, 17 July 2017
DOI: 10.1038/nmat4938