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Hydrogen is a highly attractive zero-emission energy sector. However, in many electrochemical systems, such as carbon dioxide reduction, batteries and supercapacitors hydrogen evolution reaction (HER) is an undesired competing reaction. It is therefore important to tailor these electrochemical systems in order to minimise hydrogen production. Carbon black materials are often added to the catalyst layers as they are low cost, abundant, inert, and have a high conductivity and surface area. This work has investigated HER activities for seven different commercial carbon materials to identify the required structural properties of carbon for minimizing the hydrogen evolution reaction. Rotating disk electrode, X-ray diffraction, and nitrogen adsorption/ desorption were used to determine the electrochemical and physical characteristics of the carbon materials. An on-chip electrochemical mass spectrometer was used to further probe the gaseous products being produced at the electrode insitu; we established that the exact onset of the HER at -0.4 V vs RHE, as shown in Figure 1. Furthermore, we have correlated our electrochemical experiments to earlier characterization data on the same carbon materials, including: X-ray photoelectron spectroscopy, elemental analysis (e.g. Fe, H, S, C) using neutron activation analysis.1 Our results indicate that the most graphitic carbons with low amount of metal impurities are the best for inhibiting H2 evolution. V Čolić, S. Yang, Z Révay, I E L Stephens & I Chorkendorff, Electrochim Acta, 2018, 272, 192–202. Figure 1 |
