厦门大学李剑锋团队报道了非质子Na-O₂电池氧还原反应机理表面效应的实时监测。相关研究成果发表在2021年11月23日出版的《美国化学会杂志》。

非质子钠氧（Na–O₂）电池的放电由钠离子（Na⁺-ORR）存在下的阴极氧还原反应驱动。然而，非质子性Na⁺-ORR的机制仍然不明确，并且存在系统依赖性。

该文中，研究人员首次利用原位电化学拉曼光谱研究了三种原子有序Au（hkl）单晶表面的非质子Na⁺-ORR过程，并在分子水平上确定了结构-中间体/机理关系。获得了Au（110）上的超氧物和Au（100）和Au（111）上的过氧化物作为中间体/产物的直接光谱证据。综合实验结果与理论模拟分析表明，Au(hkl)电极对非质子Na⁺-ORR活性的表面效应主要是由Na⁺和O₂的不同吸附引起的。

研究工作增强了人们对Au（hkl）表面非质子Na⁺-ORR的理解，并为改进型Na–O₂电池的设计提供了进一步的指导。

附：英文原文

Title: Real-Time Monitoring of Surface Effects on the Oxygen Reduction Reaction Mechanism for Aprotic Na–O2 Batteries

Author: Jing Zhang, Xia-Guang Zhang, Jin-Chao Dong, Petar M. Radjenovic, David James Young, Jian-Lin Yao, Ya-Xian Yuan, Zhong-Qun Tian, Jian-Feng Li

Issue&Volume: November 23, 2021

Abstract: Discharging of aprotic sodium–oxygen (Na–O2) batteries is driven by the cathodic oxygen reduction reaction in the presence of sodium cations (Na+-ORR). However, the mechanism of aprotic Na+-ORR remains ambiguous and is system dependent. In-situ electrochemical Raman spectroscopy has been employed to study the aprotic Na+-ORR processes at three atomically ordered Au(hkl) single-crystal surfaces for the first time, and the structure–intermediates/mechanism relationship has been identified at a molecular level. Direct spectroscopic evidence of superoxide on Au(110) and peroxide on Au(100) and Au(111) as intermediates/products has been obtained. Combining these experimental results with theoretical simulation has revealed that the surface effect of Au(hkl) electrodes on aprotic Na+-ORR activity is mainly caused by the different adsorption of Na+ and O2. This work enhances our understanding of aprotic Na+-ORR on Au(hkl) surfaces and provides further guidance for the design of improved Na–O2 batteries.

DOI: 10.1021/jacs.1c10009

Source: https://pubs.acs.org/doi/10.1021/jacs.1c10009