Atomically dispersed Ir Lewis acid sites on (111)-oriented CeO2 enable enhanced reaction kinetics for Li-O2 batteries

• Published in: Chemical engineering journal (Lausanne, Switzerland : 1996) Switzerland : 1996), 2024-11, Vol.500, p.156972, Article 156972
• Main Authors: Zhao, Yang, Wang, Zhen, Guan, Shuyun, Gao, Yinkun, Gong, Shusheng, Han, Guokang, Gao, Peng, Lou, Shuaifeng, Zhu, Yongming, Li, Xudong
• Format: Article
• Language: English
• Subjects: Atomically dispersed Ir; Lewis acid sites; Lithium-oxygen batteries; oriented CeO2; Reaction kinetics
• ISSN: 1385-8947
• DOI: 10.1016/j.cej.2024.156972

[Display omitted] •Remarkable performance in LOBs(11494 mAh/g ultra-high discharge capacity and 221 cycles with high current and capacity).•Single-atom dispersion of the Ir site based on the dominant exposed crystal plane of CeO2.•Determination of the structure–activity relationship between the adsorption strength of LiO2 and varied crystal planes and Lewis acidity. Non-aqueous lithium-oxygen batteries are widely regarded as one of the most promising electrochemical energy storage systems, with their ultra-high theoretical energy density and environmental friendliness. However, the sluggish oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) kinetics hinder their practical application. In this study, we tailored an atomically dispersed Ir site on a CeO2 support (Ir@CeO2) with {111} facet-dependent activity to enhance cathode reaction kinetics. The charge interaction between Ir and Ce atoms results in the appropriate regulation of the d-band center of Ir sites leaping into the Fermi energy level, demonstrating a stronger Lewis acidity, which enables easier electron injection from the Ir d-orbitals into O 2p-orbitals of LiO2. This facilitates the conversion kinetics, and as a result, the lithium-oxygen battery with Ir@CeO2 catalyst delivers a minimal discharge/charge polarization and long-term cycle stability, outperforming most traditional catalysts reported. Our promising findings offer compelling insights into the precise manipulation of d orbital structures and the optimization of Lewis acidity, paving the way for advanced electrocatalyst design.