Operando identification of the dynamic behavior of oxygen vacancy-rich Co3O4 for oxygen evolution reaction
學年 108
學期 2
出版（發表）日期 2020-06-14
作品名稱 Operando identification of the dynamic behavior of oxygen vacancy-rich Co3O4 for oxygen evolution reaction
作品名稱（其他語言）
著者 Z. Xiao; Y. C. Huang; C. L. Dong; C. Xie; Z. Liu; S. Du; W. Chen; D. Yan; L. Tao; Z. Shu; G. Zhang; H. Duan; Y. Wang; Y. Zou; R. Chen; S. Wang
單位
出版者
著錄名稱、卷期、頁數 J. Am. Chem. Soc. 142(28), 12087-12095
摘要 The exact role of a defect structure on transition metal compounds for electrocatalytic oxygen evolution reaction (OER), which is a very dynamic process, remains unclear. Studying the structure–activity relationship of defective electrocatalysts under operando conditions is crucial for understanding their intrinsic reaction mechanism and dynamic behavior of defect sites. Co3O4 with rich oxygen vacancy (VO) has been reported to efficiently catalyze OER. Herein, we constructed pure spinel Co3O4 and VO-rich Co3O4 as catalyst models to study the defect mechanism and investigate the dynamic behavior of defect sites during the electrocatalytic OER process by various operando characterizations. Operando electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV) implied that the VO could facilitate the pre-oxidation of the low-valence Co (Co2+, part of which was induced by the VO to balance the charge) at a relatively lower applied potential. This observation confirmed that the VO could initialize the surface reconstruction of VO–Co3O4 prior to the occurrence of the OER process. The quasi-operando X-ray photoelectron spectroscopy (XPS) and operando X-ray absorption fine structure (XAFS) results further demonstrated the oxygen vacancies were filled with OH• first for VO–Co3O4 and facilitated pre-oxidation of low-valence Co and promoted reconstruction/deprotonation of intermediate Co–OOH•. This work provides insight into the defect mechanism in Co3O4 for OER in a dynamic way by observing the surface dynamic evolution process of defective electrocatalysts and identifying the real active sites during the electrocatalysis process. The current finding would motivate the community to focus more on the dynamic behavior of defect electrocatalysts.
關鍵字
語言 en_US
ISSN 1520-5126
期刊性質 國外
收錄於 SCI
產學合作
通訊作者
審稿制度 是
國別 USA
公開徵稿
出版型式 ,電子版
相關連結

機構典藏連結 ( http://tkuir.lib.tku.edu.tw:8080/dspace/handle/987654321/120730 )

SDGS 氣候行動,可負擔的潔淨能源