Operando X-ray absorption spectroscopy (XAS) investigation on high entropy spinels as electrocatalysts for the oxygen evolution reaction

High entropy oxides are a promising novel class of materials, widely employed for many applications. In particular, high entropy spinels have shown excellent performances towards the oxygen evolution reaction (OER). It may be speculated that coupling many elements may lead to synergistic effects between cations, that results into a high activity notwithstanding the low cobalt content. However, to confirm this hypothesis, the use of an element-selective technique like X-ray absorption spectroscopy (XAS) is mandatory. The aim of this proposal is to carry out operando XAS on high entropy spinels, at multiple 3d transition metal K-edges, in order to establish the metal active centres and to elucidate, in turn, the mechanism of the OER reaction.