Reaction Induced Surface Restructuring in Electrocatalysts for OER

The search of efficient and stable electrocatalysts for oxygen evolution reaction (OER) in alkaline and acidic electrolytes is the key to enable the commercialization of electrolyzers and low hydrogen production price. However, there is a trade-off between activity and stability for catalysts due to the highly oxidative condition of OER, which induces the surface restructuring in electrocatalysts. This presentation will show couple of cases, including (Co, Ni)S x and SrIrO 3 -based catalysts, go through irreversible restructuring and form (metal)stable phases that exhibit higher activity (better than commercial standards IrO 2 and RuO 2 ) and better stability. Using in-situ X-ray absorption spectroscopy (XAS) and other characterizations, we reveal the true catalyst phases that all contain octahedral oxide clusters, which are responsible for the improved activity and stability. The strategy to design and scale up such active phases will also be discussed.