Competitive Adsorption and Interplay between Methanol and Water during Electro-Oxidation on Pd-Based Electrocatalyst

• Main Authors: Hernández, S.I (Author), Ledesma-Durán, A. (Author), Maya-Cornejo, J. (Author), Santamaría-Holek, I. (Author)
• Format: Article
• Language: English
• Published: IOP Publishing Ltd 2022
• Subjects: Adsorption; Alkaline conditions; Carbon dioxide; Competitive adsorption; Electrocatalysis; Electrocatalysts; Electrochemical response; Electrode kinetics; Electrode Kinetics; Electrooxidation; Electrooxidations; Fuel cells; Fuel Cells; Integral equations; Methanol; Methanol oxidation reactions; Methanol-water; Pd-based electrocatalysts; Reaction mechanism; Reaction under
• Online Access: View Fulltext in Publisher

 The methanol oxidation reaction on palladium-based materials at different concentrations is studied theoretically and experimentally through its electrochemical response. Using a well-established reaction mechanism for the methanol oxidation reaction under alkaline conditions, we analyze the role of methanol, water adsorption and oxidation steps on the total electrochemical current obtained from linear voltammetry experiments. Solving the kinetic equations numerically, we fit the data obtained from experiments performed with a commercial catalyst at different methanol concentrations. Comparison of the numerical calculations with analytical expressions deduced following Laviron s theoretical approach leads to discerning the adsorption contributions from methanol and water to the overall shape of the oxidation current from the nonlinear contribution associated with carbon-dioxide production. This identification allows, in turn, to use the peak current of the adsorption-related processes as a tool to characterize the overall catalyst's performance. © 2022 The Author(s). Published on behalf of The Electrochemical Society by IOP Publishing Limited. This is an open access article distributed under the terms of the Creative Commons Attribution 4.0 License (CC BY, http://creativecommons.org/licenses/by/4.0/), which permits unrestricted reuse of the work in any medium, provided the original work is properly cited. [DOI: 10.1149/1945-7111/ac6321].