Simple Aqueous Preparation of High Activity and Stability NiFe Hydrous Oxide Catalysts for Water Oxidation

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• 作者：Chao Wang ; Reza B. Moghaddam ; Michael J. Brett ; Steven H. Bergens
• 刊名：ACS Sustainable Chemistry & Engineering
• 出版年：2017
• 出版时间：January 3, 2017
• 年：2017
• 卷：5
• 期：1
• 页码：1106-1112
• 全文大小：412K
• ISSN：2168-0485

文摘

A series of Ni_1–xFe_x hydrous oxide nanoparticles (HO-nps, x = 0–0.5, 1) were prepared by stirring 0.1 M KOH solutions of NiCl₂ and FeCl₂ under air at room temperature. The resulting HO-nps can be used directly, or washed and isolated without loss of activity. The Ni_1–xFe_x HO-nps are outstandingly active and stable toward the water oxidation reaction (WOR) in base. The Ni_0.75Fe_0.25 HO-np was the most active mass-normalized WOR catalyst in the series, with onset overpotential = 190 mV, Tafel slope = 24 mV dec^–1, overpotential at 10 mA cm^–2 = 234 mV, and loadings Ni + Fe = 0.135 mg cm^–2. The catalysts were robust under long-term galvanostatic and duty-cycle testing. The Ni_0.75Fe_0.25 HO-np catalyst has a layered double hydroxide structure, and it appears that Fe enhances the activity of Ni toward the WOR by decreasing its electron density.