Fast and accurate determination of the electroactive surface area of MnOx

• Published in: Electrochimica acta Vol. 389; p. 138692
• Main Authors: Aufa, Muhamad H., Watzele, Sebastian A., Hou, Shujin, Haid, Richard W., Kluge, Regina M., Bandarenka, Aliaksandr S., Garlyyev, Batyr
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01.09.2021; Elsevier BV
• Subjects: Adsorption; Electrocatalysis; Electrocatalysts; Electrochemical active surface area; Electrochemical impedance spectroscopy; Impedance spectroscopy; Manganese; Manganese oxide; Nanostructured materials; Oxygen evolution reaction; Oxygen evolution reactions; Reaction intermediates; Surface area; Surface chemistry; Electrochemical active surface area; Electrocatalysis; Impedance spectroscopy; Oxygen evolution reaction; Manganese oxide
• ISSN: 0013-4686; 1873-3859
• DOI: 10.1016/j.electacta.2021.138692

Manganese oxide (MnOx)-based materials are widely utilized in the field of electrocatalysis as bifunctional electrocatalysts for the oxygen reduction and evolution reactions. However, for an accurate assessment of their performance, the determination of their electrochemical active surface area (ECSA) is of paramount importance. So far, there is no fast and reproducible methodology. This article presents an easily applicable and affordable technique to determine the ECSA of MnOx accurately. The presented methodology makes use of the specific adsorption capacitance of reaction intermediates close to the onset potential of the oxygen evolution reaction. The electrochemical impedance spectroscopy is utilized to measure the specific adsorption capacitances at different potentials. Using MnOx thin-film electrodes, we determine the specific adsorption capacitances and present calibration values, which can be used for an accurate determination of the ECSA of different, for instance, nanostructured materials. [Display omitted]