Controlling oxygen electrocatalysis on model oxide surfaces using electrolyte design

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The oxygen evolution reaction (OER) is one of the most fundamental processes for energy storage both in nature and technology. The high overpotential of the OER is one of the grand challenges faced in oxygen electrocatalysis and significant improvement is key for sustainable production of renewable energy carriers in a future hydrogen economy. Virtually all previous studies of activity and mechanism focused on the composition and structure of the catalytic electrode, while this project focuses on the influence of the electrolyte to identify structure-activity relationships. It is expected that hydrogen bonding can lower the relative formation energies of intermediates and products, which will lead to a reduction of the high overpotential of the reaction. The strength of hydrogen bonding in ionic liquids can be tuned systematically, thereby making them ideal model electrolytes to derive novel descriptors of activity and product yield. Oxygen evolution in model electrolytes with defined amounts of water will be detected by differential electrochemical mass spectroscopy (DEMS), while peroxide species will be simultaneously measured using a channel electrode. The proposed approach is generalizable to other insufficiently understood multi-step reactions on electrocatalytic surfaces, which offers new avenues to understand mechanisms and active sites of electrocatalysis for optimizing their activity.