Electro-catalytic activity of Ni–Co-based catalysts for oxygen evolution reaction

Journal Article · Wed Apr 15 00:00:00 EDT 2015 · Materials Research Bulletin

DOI:https://doi.org/10.1016/J.MATERRESBULL.2014.12.063· OSTI ID:22475728

Ju, Hua ^[1]; Li, Zhihu ^[2]; Xu, Yanhui ^[2]

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1. School of Urban Rail Transportation, Soochow University, Suzhou 215006 (China)
2. College of Physics, Optoelectronics and Energy, Soochow University, Moye Rd. 688, Suzhou 215006 (China)

Graphical abstract: The electro-catalytic activity of different electro-catalysts with a porous electrode structure was compared considering the real electrode area that was evaluated by cyclic measurement. - Highlights: • Ni–Co-based electro-catalysts for OER have been studied and compared. • The real electrode area is calculated and used for assessing the electro-catalysts. • Exchange current and reaction rate constant are estimated. • Ni is more useful for OER reaction than Co. - Abstract: In the present work, Ni–Co-based electrocatalysts (Ni/Co = 0:6, 1:5, 2:4, 3:3, 4:2, 5:1 and 6:0) have been studied for oxygen evolution reaction. The phase structure has been analyzed by X-ray diffraction technique. Based on the XRD and SEM results, it is believed that the synthesized products are poorly crystallized. To exclude the disturbance of electrode preparation technology on the evaluation of electro-catalytic activity, the real electrode surface area is calculated based on the cyclic voltammetry data, assumed that the specific surface capacitance is 60 μF cm{sup −2} for metal oxide electrode. The real electrode area data are used to calculate the current density. The reaction rate constant of OER at different electrodes is also estimated based on basic reaction kinetic equations. It is found that the exchange current is 0.05–0.47 mA cm{sup −2} (the real surface area), and the reaction rate constant has an order of magnitude of 10{sup −7}–10{sup −6} cm s{sup −1}. The influence of the electrode potential on OER rate has been also studied by electrochemical impedance spectroscopy (EIS) technique. Our investigation has shown that the nickel element has more contribution than the cobalt; the nickel oxide has the best electro-catalytic activity toward OER.

• OSTI ID: 22475728
• Journal Information: Materials Research Bulletin, Vol. 64; Other Information: Copyright (c) 2014 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA); ISSN 0025-5408
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
CAPACITANCE
COBALT COMPOUNDS
COMPARATIVE EVALUATIONS
CONCENTRATION RATIO
DISTURBANCES
ELECTROCATALYSTS
ELECTROCHEMISTRY
ELECTRODES
NICKEL COMPOUNDS
NICKEL OXIDES
OXYGEN
OXYGEN ENHANCEMENT RATIO
POROUS MATERIALS
SCANNING ELECTRON MICROSCOPY
SPECTROSCOPY
SURFACE AREA
SURFACES
VOLTAMETRY
X-RAY DIFFRACTION