Invited talk - Transient dynamics of M-Xides (X = B and P) during electrocatalysis and design considerations for industrially functional stable electrodes

Abstract

The so-called M-Xides (X = B, P, S, Se) have attracted great attention in electrocatalytic oxygen evolution. These materials notably undergo irreversible reconstruction under anodic polarization with formation of MX@MO x H y (Core@shell) as transient structures. Structural transformation and formation of MX@MO x H y is accompanied with dissolution of the guest elements. In the presence of iron impurities in the electrolyte, a complex form of interaction ensues leading to further activity enhancement. Underpinning the origins of activity enhancement in light of these competing interactions is complex to decipher albeit necessary to inform the design of advanced catalysts. In this presentation, atomic- and nano-scale structural and compositional studies prior-to and in the aftermath of electrocatalysis featuring studies on individual nanoparticles and observations by atomic probe tomography (ATP), coupled with chemical and electrochemical dissolution studies on individual and particle ensembles will be used to highlight spatio-temporal dynamics of the host-guest atoms in selected model catalysts and the potential impact on the long-term activity and stability of the catalysts. Finally, some concepts for designing functional electrodes, from active powers towards industrially relevant electrodes, will be presented with highlights from a very successful recent example.