Proceedings of Materials for Sustainable Development Conference (MAT-SUS) (NFM22)
DOI: https://doi.org/10.29363/nanoge.nfm.2022.054
Publication date: 11th July 2022
The production of green hydrogen for water electrolysis is very promising for the development of a zero-carbon-emission energy structure. However, proton exchange membrane (PEM) electrolyzers, which operate in acidic media, are limited by the slow kinetics of the oxygen evolution reaction (OER) at the anode. Additionally, the anode requires high amounts of scarce precious metals like Ir as catalysts1. An inherent need for developing preparation methods to decrease mass loadings and enhance activity and stability has therefore arisen. We introduce a feasible and easy way to prepare IrOx catalysts by galvanic displacement of electrodeposited Co and Ni on polycrystalline Au surfaces. We performed the electrodeposition of Co and Ni on gold beads in a deep eutectic solvent (DES) – a non-toxic solvent with a broad potential window and high solubility of many metals2. We fabricated Ir nanoparticles by employing galvanic displacement of Co and Ni in aqueous solutions of IrCl4, and then electrochemically oxidized the metallic Ir. Our preparation of IrOx catalysts replaces complicated plating methods by the galvanic displacement technique and replaces the use of surfactant agents during electrodeposition by a green DES electrolyte. We evaluated the activity and stability of the IrOx catalysts with state-of-the-art Ir-based catalysts. The IrOx-Ni displayed enhanced activity and stability in relation to the IrOx-Co in line with previous reports3.