Hydration-Effect-Promoting Ni-Fe Oxyhydroxide Catalysts for Neutral Water Oxidation

Ning Wang; Zhen Cao; Xueli Zheng; Bo Zhang; Sergey M Kozlov; Peining Chen; Chengqin Zou; Xiangbin Kong; Yunzhou Wen; Min Liu; Yansong Zhou; Cao Thang Dinh; Lirong Zheng; Huisheng Peng; Ying Zhao; Luigi Cavallo; Xiaodan Zhang; Edward H Sargent

doi:10.1002/adma.201906806

Hydration-Effect-Promoting Ni-Fe Oxyhydroxide Catalysts for Neutral Water Oxidation

Adv Mater. 2020 Feb;32(8):e1906806. doi: 10.1002/adma.201906806. Epub 2020 Jan 16.

Authors

Ning Wang^{1

2

3

4

5}, Zhen Cao⁶, Xueli Zheng⁵, Bo Zhang⁷, Sergey M Kozlov⁶, Peining Chen^{5

7}, Chengqin Zou⁵, Xiangbin Kong^{1

2

3

4}, Yunzhou Wen⁷, Min Liu⁵, Yansong Zhou⁵, Cao Thang Dinh⁵, Lirong Zheng⁸, Huisheng Peng⁷, Ying Zhao^{1

2

3

4}, Luigi Cavallo⁶, Xiaodan Zhang^{1

2

3

4}, Edward H Sargent⁵

Affiliations

¹ Institute of Photoelectronic Thin Film Devices and Technology of Nankai University, Tianjin, 300350, P. R. China.
² Key Laboratory of Photoelectronic Thin Film Devices and Technology of Tianjin, Tianjin, 300350, P. R. China.
³ Collaborative Innovation Center of Chemical Science and Engineering, Tianjin, 300350, P. R. China.
⁴ Renewable Energy Conversion and Storage Center of Nankai University, Tianjin, 300072, P. R. China.
⁵ Department of Electrical and Computer Engineering, University of Toronto, 35 St George Street, Toronto, Ontario, M5S 1A4, Canada.
⁶ Physical Sciences and Engineering Division (PSE), KAUST Catalysis Center (KCC), King Abdullah University of Science and Technology (KAUST), Thuwal, 23955-6900, Saudi Arabia.
⁷ State Key Laboratory of Molecular Engineering of Polymers, Department of Macromolecular Science and Laboratory of Advanced Materials, Fudan University, Shanghai, 200438, China.
⁸ Beijing Synchrotron Radiation Facility, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing, 100049, China.

PMID: 31950562
DOI: 10.1002/adma.201906806

Abstract

Oxygen evolution reaction (OER) catalysts that function efficiently in pH-neutral electrolyte are of interest for biohybrid fuel and chemical production. The low concentration of reactant in neutral electrolyte mandates that OER catalysts provide both the water adsorption and dissociation steps. Here it is shown, using density functional theory simulations, that the addition of hydrated metal cations into a Ni-Fe framework contributes water adsorption functionality proximate to the active sites. Hydration-effect-promoting (HEP) metal cations such as Mg²⁺ and hydration-effect-limiting Ba²⁺ into Ni-Fe frameworks using a room-temperature sol-gel process are incorporated. The Ni-Fe-Mg catalysts exhibit an overpotential of 310 mV at 10 mA cm^-2 in pH-neutral electrolytes and thus outperform iridium oxide (IrO₂ ) electrocatalyst by a margin of 40 mV. The catalysts are stable over 900 h of continuous operation. Experimental studies and computational simulations reveal that HEP catalysts favor the molecular adsorption of water and its dissociation in pH-neutral electrolyte, indicating a strategy to enhance OER catalytic activity.

Keywords: Ni-Fe catalysts; hydration effect; neutral electrolytes; oxygen evolution reaction.

Abstract

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