Atomic Iridium Incorporated in Cobalt Hydroxide for Efficient Oxygen Evolution Catalysis in Neutral Electrolyte. Issue 18 (25th March 2018)

• Record Type: Journal Article
• Authors: Zhang, Youkui; Wu, Chuanqiang; Jiang, Hongliang; Lin, Yunxiang; Liu, Hengjie; He, Qun; Chen, Shuangming; Duan, Tao; Song, Li
• Is Part Of: Advanced materials. Volume 30:Issue 18(2018)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2018-03-25
• Subjects: atomic iridium -- cobalt hydroxide -- neutral electrolyte -- oxygen evolution reaction -- X‐ray absorption spectra; Materials -- Periodicals; Chemical vapor deposition -- Periodicals; 620.11
• DOI: 10.1002/adma.201707522
• Languages: English
• ISSNs: 0935-9648

Abstract

Abstract: Developing highly efficient catalysts for oxygen evolution reaction (OER) in neutral media is extremely crucial for microbial electrolysis cells and electrochemical CO2 reduction. Herein, a facile one‐step approach is developed to synthesize a new type of well‐dispersed iridium (Ir) incorporated cobalt‐based hydroxide nanosheets (nominated as CoIr) for OER. The Ir species as clusters and single atoms are incorporated into the defect‐rich hydroxide nanosheets through the formation of rich Co–Ir species, as revealed by systematic synchrotron radiation based X‐ray spectroscopic characterizations combining with high‐angle annular dark‐field scanning transmission electron microscopy measurement. The optimized CoIr with 9.7 wt% Ir content displays highly efficient OER catalytic performance with an overpotential of 373 mV to achieve the current density of 10 mA cm −2 in 1.0m phosphate buffer solution, significantly outperforming the commercial IrO2 catalysts. Further characterizations toward the catalyst after undergoing OER process indicate that unique Co oxyhydroxide and high valence Ir species with low‐coordination structure are formed due to the high oxidation potentials, which authentically contributes to superior OER performance. This work not only provides a state‐of‐the‐art OER catalyst in neutral media but also unravels the root of the excellent performance based on efficient structural identifications. Abstract : Atomic iridium incorporated in a cobalt hydroxide nanosheet is synthesized and used as an oxygen evolution reaction (OER) catalyst in neutral electrolyte. Elaborate structural identifications toward the reconstruction‐derived components strongly indicate that unique Co oxyhydroxide and high valence Ir species with low‐coordination structure are formed due to the high oxidation potentials, which authentically contributes to superior OER performance.