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

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 exchangemore » 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.« less
Authors:
 [1] ;  [2] ;  [2]
  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)
Publication Date:
OSTI Identifier:
22475728
Resource Type:
Journal Article
Resource Relation:
Journal Name: Materials Research Bulletin; Journal Volume: 64; Other Information: Copyright (c) 2014 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
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