A molecular-level description of the oxygen evolution reaction using in situ spectroscopy

Speaker: Rosa Arrigo, University of Salford

Water electrolysis stands as a cornerstone technology for green hydrogen production from renewable energy and consists of two half-cell reactions: the hydrogen evolution reaction (HER) and the oxygen evolution reaction (OER). The sluggish kinetics of the state-of-the-art OER electrocatalysts based on iridium oxide severely limit the overall efficiency of the process and, consequently, its economic viability. An in-depth comprehension of the atomic-level mechanisms governing this reaction is considered essential for designing enhanced materials and advancing the transition to a sustainable and resilient energy sector. In situ structural characterization techniques, such as X-ray absorption spectroscopy and X-ray photoelectron spectroscopy, serve this purpose well as they enable real-time monitoring of the chemical composition, structural phase, and electronic configuration of the species at the gas/liquid/solid interface during the interfacial electrocatalytic turnover. In this talk, I will present an overview of the experimental approaches developed in our group and by others to probe the reactive interface during OER , as well as our current understanding of the reaction mechanism on Ir-O-based systems gained using both soft and hard X-ray spectroscopic techniques.