Comparative DEMS study on the electrochemical oxidation of carbon blacks

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• 作者：Sean J. Ashton ; Matthias Arenz
• 关键词：DEMS ; Carbon oxidation reaction ; PEM fuel cell ; Carbon corrosion ; Carbon supports
• 刊名：Journal of Power Sources
• 出版年：2012
• 出版时间：1 November, 2012
• 年：2012
• 卷：217
• 期：Complete
• 页码：392-399
• 全文大小：998 K

文摘

The intention of the study presented here is to compare the electrochemical oxidation tendencies of a pristine Ketjen Black EC300 high surface area (HSA) carbon black, and four graphitised counterparts heat-treated between 2100 and 3200?¡ãC, such as those typically used as corrosion resistant carbon (CRC) supports for polymer electrolyte membrane fuel cell (PEMFC) catalysts. A methodology combining cyclic voltammetry (CV) and differential electrochemical mass spectrometry (DEMS) is used, which allows the characterisation and comparison of the complete electrochemical oxidation rates and behaviours of the various carbon blacks. It is observed that the behaviour of the carbon black towards electrochemical oxidation is highly dynamic, and dependent on the properties of the pristine carbon back, the degree of electrochemical oxidation and the potential pre-history. The behaviour of the non-graphitised and CRC samples graphitised ¡Ü2450?¡ãC suggests that electrochemical oxidation leads to the passivation of the carbon, which when reduced in a potential excursion to ¡Ü0.24?V_RHE is lost allowing subsequent oxidation; however, CRC samples graphitised ¡Ý2800?¡ãC did not exhibit this same behaviour.