Electrochemically active Ir NPs on graphene for OER in acidic aqueous electrolyte investigated by in situ and ex situ spectroscopies

Velasco-Vélez, JJ; Jones, TE; Streibel, V; Hävecker, M; Chuang, CH; Frevel, L; Plodinec, M; Centeno, A; Zurutuza, A; Wang, R; Arrigo, R; Mom, R; Hofmann, S; Schlögl, R; Knop-Gericke, A

Abstract

An electrode for the oxygen evolution reaction based on a conductive bi-layered free standing graphene support functionalized with iridium nanoparticles was fabricated and characterized by means of potentiometric and advanced X-ray spectroscopic techniques. It was found that the electrocatalytic activity of iridium nanoparticles is associated to the formation of Ir 5d electron holes. Strong Ir 5d and O 2p hybridization, however, leads to a concomitant increase O 2p hole character, making oxygen electron deficient and susceptible to nucleophilic attack by water. Consequently, more efficient electrocatalysts can be synthesized by increasing the number of electron-holes shared between the metal d and oxygen 2p.

• Journal Article Type: Article
• Acceptance Date: Oct 27, 2018
• Online Publication Date: Oct 31, 2018
• Publication Date: Oct 31, 2018
• Deposit Date: Mar 26, 2019
• Journal: Surface Science
• Print ISSN: 0039-6028
• Publisher: Elsevier
• Volume: 681
• Issue: Mar 19
• Pages: 1-8
• DOI: https://doi.org/10.1016/j.susc.2018.10.021
• Publisher URL: https://doi.org/10.1016/j.susc.2018.10.021
• Related Public URLs: https://www.sciencedirect.com/journal/surface-science/vol/681/suppl/C