IrO(2)-SiO(2) binary oxide films: Geometric or kinetic interpretation of the improved electrocatalytic activity for the oxygen evolution reaction

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	IrO(2)-SiO(2) binary oxide films: Geometric or kinetic interpretation of the improved electrocatalytic activity for the oxygen evolution reaction
	J. J. Zhang; J. M. Hu; J. Q. Zhang; C. N. Cao
	2011
发表期刊	International Journal of Hydrogen Energy
ISSN	0360-3199
卷号	36 期号:9 页码:5218-5226
摘要	Our previous paper (Electrochim Acta 2010; 55: 4587-4593) reported that doping silica, the largest reserved oxide in the world, significantly improved the apparent electrochemical activity of Ti/IrO(2) electrodes for oxygen evolution reaction (OER). In the present work, the electrochemical surface structure of Ti/IrO(2) SiO(2) composite electrodes and the reaction kinetics of the OER thereon are investigated in details, to deeper understand the positive role of silica incorporation. Both the cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) measurements indicate either "inner" or "outer" active surface area of the mixed oxide electrodes, which is quantified by the voltammetric charge (q*) or by the double-layer capacitance (C(dl)), constantly increases when increasing the silica content therein under the investigated range of Ir/Si molar ratio. The "porosity", defined as the ratio of the "inner" to "total" surface area, of the binary oxide films exhibits much higher values than pure IrO(2) film. Although the apparent electrocatalytic activity for the OER at composite electrodes is obviously higher than that at IrO(2) electrode, the real surface area-normalized activity declines after silica incorporation. The kinetic rate constants of the OER, approximated from the normalized polarization curves, also show dramatically decreased values at silica-doped electrodes. The above-mentioned results suggest that the enhanced apparent electrocatalytical activity of silica-doped IrO(2) electrodes might be merely a result of geometric effect. Copyright (C) 2011, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.
部门归属	[zhang, jia-jia; hu, ji-ming; zhang, jian-qing; cao, chu-nan] zhejiang univ, dept chem, hangzhou 310027, peoples r china. [zhang, jian-qing; cao, chu-nan] state key lab corros & protect, shenyang 110016, peoples r china.;hu, jm (reprint author), zhejiang univ, dept chem, hangzhou 310027, peoples r china;kejmhu@zju.edu.cn
关键词	Iro(2) Electrode Sio(2) Doping Electrochemical Surface Structure Electrocatalytic Activity Electrochemical Surface Characterization Pem Water Electrolysis X-ray-diffraction Iro2-based Electrodes Cyclic Voltammetry Alkaline-solution Co3o4 Electrodes Ruo2 Electrodes Iridium Oxide Acid-solution
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文献类型	期刊论文
条目标识符	http://ir.imr.ac.cn/handle/321006/30888
专题	中国科学院金属研究所
推荐引用方式 GB/T 7714	J. J. Zhang,J. M. Hu,J. Q. Zhang,et al. IrO(2)-SiO(2) binary oxide films: Geometric or kinetic interpretation of the improved electrocatalytic activity for the oxygen evolution reaction[J]. International Journal of Hydrogen Energy,2011,36(9):5218-5226.
APA	J. J. Zhang,J. M. Hu,J. Q. Zhang,&C. N. Cao.(2011).IrO(2)-SiO(2) binary oxide films: Geometric or kinetic interpretation of the improved electrocatalytic activity for the oxygen evolution reaction.International Journal of Hydrogen Energy,36(9),5218-5226.
MLA	J. J. Zhang,et al."IrO(2)-SiO(2) binary oxide films: Geometric or kinetic interpretation of the improved electrocatalytic activity for the oxygen evolution reaction".International Journal of Hydrogen Energy 36.9(2011):5218-5226.