Electrochemical dealloying of metallic glasses for the design of new nanostructured electrodes for green hydrogen evolution

• Applicant: Professorin Dr.-Ing. Viktoria Shtefan, Ph.D.
• Subject Area: Synthesis and Properties of Functional Materials ; Thermodynamics and Kinetics as well as Properties of Phases and Microstructure of Materials
• Term: since 2024
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 553576450

Multicomponent metallic glasses (MGs) are gaining world-wide a rapidly growing research interest with respect to urgently needed new developments of electrode materials for green hydrogen production by water electrolysis. This is due to their possible broad compositional ranges and their unique single-phase amorphous nature with intrinsically high energy states. Latterly, MGs are considered as ideally homogeneous precursor alloys for innovative dealloying concepts to generate functional nanostructures. The present work aims at developing a new approach for the generation of nanostructured (nanoporous) electrode materials for efficient cathodic hydrogen evolution in alkaline water electrolysis. This is based on specifically designed non-precious metallic glass-forming alloys and a new concept for electrochemical dealloying treatments. The related fundamental aspects of glass formation and stability as well as of reactions mechanisms of the dealloying process will be revealed and discussed. The relations between generated metallic nanostructures and achievable electrode performances will be described. The project comprises firstly the design, fabrication and characterization of suitable Zr-based precursor alloys with high glass-forming ability. This is implemented by an element substitution strategy in accordance with principal criteria for glass formation and accompanied by structural, chemical and thermal materials analysis. Further, a method for homogeneous dealloying of those glassy alloys will be developed which is based on special electrochemical treatments in sustainable electrolytes. The targeted nanoligament states with new phase compositions and expected synergetic electrocatalytic effect will be in-depth analysed by means of advanced materials and surface analytical methods. The electrode performance of the nanostructured electrode materials for hydrogen reduction will be investigated by half-cell experiments in alkaline electrolytes. This comprises besides regular electrocatalytic testing methods also a first evaluation of their corrosion stability in approximate electrolysis conditions. An assessment of the achieved performance data in comparison to those for established electrode materials and other nanostructured R&D materials will be done. A proof of concept comprises also first tests of most promising new electrode materials in accordance with EC Key Performance Indicators (KPIs) for water electrolysis.

• DFG Programme: Research Grants