Details

Autor(en) / Beteiligte

• Zhou, Jing
• Zhang, Linjuan
• Huang, Yu-Cheng
• Dong, Chung-Li
• Lin, Hong-Ji
• Chen, Chien-Te
• Tjeng, L H
• Hu, Zhiwei

Titel

Voltage- and time-dependent valence state transition in cobalt oxide catalysts during the oxygen evolution reaction

Ist Teil von

• Nature communications, 2020-04, Vol.11 (1), p.1984-1984, Article 1984

Ort / Verlag

England: Nature Publishing Group

Erscheinungsjahr

2020

Link zum Volltext

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• The ability to determine the electronic structure of catalysts during electrochemical reactions is highly important for identification of the active sites and the reaction mechanism. Here we successfully applied soft X-ray spectroscopy to follow in operando the valence and spin state of the Co ions in Li Co O under oxygen evolution reaction (OER) conditions. We have observed that a substantial fraction of the Co ions undergo a voltage-dependent and time-dependent valence state transition from Co to Co accompanied by spontaneous delithiation, whereas the edge-shared Co-O network and spin state of the Co ions remain unchanged. Density functional theory calculations indicate that the highly oxidized Co site, rather than the Co site or the oxygen vacancy site, is mainly responsible for the high OER activity.