Details

Autor(en) / Beteiligte

• Wei, Yicheng
• Hu, Yang
• Da, Pengfei
• Weng, Zheng
• Xi, Pinxian
• Yan, Chun-Hua

Titel

Triggered lattice-oxygen oxidation with active-site generation and self-termination of surface reconstruction during water oxidation

Ist Teil von

• Proceedings of the National Academy of Sciences - PNAS, 2023-12, Vol.120 (50), p.e2312224120-e2312224120

Ort / Verlag

United States: National Academy of Sciences

Erscheinungsjahr

2023

Quelle

EZB Electronic Journals Library

Beschreibungen/Notizen

• To master the activation law and mechanism of surface lattice oxygen for the oxygen evolution reaction (OER) is critical for the development of efficient water electrolysis. Herein, we propose a strategy for triggering lattice-oxygen oxidation and enabling non-concerted proton-electron transfers during OER conditions by substituting Al in La Sr CoO . According to our experimental data and density functional theory calculations, the substitution of Al can have a dual effect of promoting surface reconstruction into active Co oxyhydroxides and activating deprotonation on the reconstructed oxyhydroxide, inducing negatively charged oxygen as an active site. This leads to a significant improvement in the OER activity. Additionally, Al dopants facilitate the preoxidation of active cobalt metal, which introduces great structural flexibility due to elevated O 2 levels. As OER progresses, the accumulation of oxygen vacancies and lattice-oxygen oxidation on the catalyst surface leads to the termination of Al leaching, thereby preventing further reconstruction. We have demonstrated a promising approach to achieving tunable electrochemical reconstruction by optimizing the electronic structure and gained a fundamental understanding of the activation mechanism of surface oxygen sites.