Electro-oxidation and reduction of H2 on platinum studied by scanning electrochemical microscopy for the purpose of local detection of H2 evolution

• Published in: Surface and interface analysis Vol. 47; no. 13; pp. 1187 - 1191
• Main Authors: Jamali, Sina S., Moulton, Simon E., Tallman, Dennis E., Weber, Jan, Wallace, Gordon G.
• Format: Journal Article
• Language: English
• Published: Blackwell Publishing Ltd 01.12.2015
• Subjects: H2 detection; H2 electro-oxidation; H2 electro-reduction; H2/H+ redox recycling; scanning electrochemical microscopy
• ISSN: 0142-2421; 1096-9918
• DOI: 10.1002/sia.5874

Electrochemical detection of H2 using scanning electrochemical microscopy (SECM) has shown to hold great promise as a sensitive characterization method with high spatial resolution for active surfaces generating H2. Herein, the factors contributing to the current that is measured by SECM in generation/collection mode for H2 detection are studied. In particular, the concentration gradient of H2 at the substrate, the H2/H+ recycling between the SECM tip and substrate and hemispherical profile of H2 diffusion has been discussed. It was postulated that H2/H+ recycling plays a dominant role in the oxidative current measured in generation/collection mode of SECM when the microelectrode is positioned in close vicinity of substrate. Copyright © 2015 John Wiley & Sons, Ltd.