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arXiv · 1807.08546

The role of metastability in enhancing water-oxidation activity

Nathalie Vonrüti·Ulrich Aschauer
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Abstract

While metastability enhanced water-oxidation activity was experimentally reported, the reason behind this effect is still unclear. We determine here, using density functional theory calculations, oxygen evolution reaction overpotentials for a variety of defective (001) surfaces of three different perovskite materials. For all three, we find a large range of overpotentials for different reaction sites including also overpotentials at the top of the activity volcano. Assuming that these sites dominate the apparent catalytic activity, this implies that a large number of geometrically different reaction sites, as they occur when a catalyst is operated at the border of its stability conditions, can lead to a strong enhancement of the apparent activity. This also implies that a pre-treatment of the catalyst creating a variety of different reactive sites could lead to superior catalytic activities for thermodynamically stable materials.

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Nathalie Vonrüti, Ulrich Aschauer. 2018-07-23. The role of metastability in enhancing water-oxidation activity. https://doi.org/10.1039/c9cp04859f

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