S. I. Nefedkin, A. V. Ryabukhin, V. E. Eletskikh, R. G. Boldin, V. D. Mikhnevich, M. A. Klimova
{"title":"Magnetron Technology for Manufacturing of Electrodes for Electrolyzers with Proton-Exchange Membranes","authors":"S. I. Nefedkin, A. V. Ryabukhin, V. E. Eletskikh, R. G. Boldin, V. D. Mikhnevich, M. A. Klimova","doi":"10.1134/s1023193524030091","DOIUrl":null,"url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>The results of the development and study of catalysts for the anodes of water splitting electrolyzers with a proton exchange membrane are presented. To deposit catalytic layers on a titanium support, the method of magnetron sputtering of composite targets in a vacuum was used. Iridium and ruthenium are used as the principal catalysts; molybdenum, chromium, and titanium, as functional additives. The electrochemical and structural characteristics of catalytic coatings are studied. Using voltammetry methods, cyclic voltammograms and anodic characteristics of the catalytic compositions are obtained, in particular, at different temperatures of the subsequent heat treatment in air, as well as at different measurement temperatures. The Tafel slopes of the current–voltage characteristics of the composite anodes, as well as the currents at a potential of 1.55 V (RHE) are determined. The minimal slopes are obtained for the Ir–Ru–Mo–Ti catalytic composition (<i>b</i> = 40–63 mV/decade); the maximal currents, for the Ir–Mo–Cr catalytic composition (<i>i</i> = 100–110 mA/cm<sup>2</sup> at <i>E</i> = 1.55 V (RHE)). The magnitude of adsorption currents in the anodic potential region of cyclic voltammograms is shown to correlate with the coefficient <i>b</i> of the Tafel equation (<i>E</i> vs. log<i>i</i>); it determines the number of catalytic centers for the deprotonation stage in the oxygen evolution reaction. However, the catalyst activity in the oxygen evolution reaction is determined not only by the number of these centers but mainly by the functional features of the catalyst proper, i.e., the composition of the catalyst and the conditions for its preparation (including the temperature of the catalyst subsequent heat treatment in air). The iridium-based catalytic compositions added with molybdenum and chromium have higher activity in the oxygen evolution reaction. Structural studies showed that during the magnetron sputtering of the composite targets, even with small catalyst loading, dispersed structures are formed; in the real porous titanium anodes, these structures must form on the front surfaces with higher catalyst content.</p>","PeriodicalId":760,"journal":{"name":"Russian Journal of Electrochemistry","volume":null,"pages":null},"PeriodicalIF":1.1000,"publicationDate":"2024-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Russian Journal of Electrochemistry","FirstCategoryId":"5","ListUrlMain":"https://doi.org/10.1134/s1023193524030091","RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q4","JCRName":"ELECTROCHEMISTRY","Score":null,"Total":0}
引用次数: 0
Abstract
The results of the development and study of catalysts for the anodes of water splitting electrolyzers with a proton exchange membrane are presented. To deposit catalytic layers on a titanium support, the method of magnetron sputtering of composite targets in a vacuum was used. Iridium and ruthenium are used as the principal catalysts; molybdenum, chromium, and titanium, as functional additives. The electrochemical and structural characteristics of catalytic coatings are studied. Using voltammetry methods, cyclic voltammograms and anodic characteristics of the catalytic compositions are obtained, in particular, at different temperatures of the subsequent heat treatment in air, as well as at different measurement temperatures. The Tafel slopes of the current–voltage characteristics of the composite anodes, as well as the currents at a potential of 1.55 V (RHE) are determined. The minimal slopes are obtained for the Ir–Ru–Mo–Ti catalytic composition (b = 40–63 mV/decade); the maximal currents, for the Ir–Mo–Cr catalytic composition (i = 100–110 mA/cm2 at E = 1.55 V (RHE)). The magnitude of adsorption currents in the anodic potential region of cyclic voltammograms is shown to correlate with the coefficient b of the Tafel equation (E vs. logi); it determines the number of catalytic centers for the deprotonation stage in the oxygen evolution reaction. However, the catalyst activity in the oxygen evolution reaction is determined not only by the number of these centers but mainly by the functional features of the catalyst proper, i.e., the composition of the catalyst and the conditions for its preparation (including the temperature of the catalyst subsequent heat treatment in air). The iridium-based catalytic compositions added with molybdenum and chromium have higher activity in the oxygen evolution reaction. Structural studies showed that during the magnetron sputtering of the composite targets, even with small catalyst loading, dispersed structures are formed; in the real porous titanium anodes, these structures must form on the front surfaces with higher catalyst content.
期刊介绍：
Russian Journal of Electrochemistry is a journal that covers all aspects of research in modern electrochemistry. The journal welcomes submissions in English or Russian regardless of country and nationality of authors.
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