Exploring high-entropy alloys for the hydrogen evolution reaction in alkaline electrocatalysis: from compositional screening to strain effects

• Applicants: Professorin Dr.-Ing. Corina Andronescu; Professor Dr.-Ing. Alfred Ludwig
• Subject Area: Physical Chemistry of Solids and Surfaces, Material Characterisation ; Analytical Chemistry ; Synthesis and Properties of Functional Materials ; Mechanical Properties of Metallic Materials and their Microstructural Origins
• Term: from 2020 to 2024
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 440951282

The project explores high entropy alloy (HEA) thin film materials libraries as electrocatalysts for the HER in alkaline environments and investigates mechanical strain effects on catalysis on selected HEA films with the aims to identify new catalysts and unravel new mechanisms to modulate catalyst activity based on multinary composition and strain states. In the first part of the project a large set of HEA systems based on abundant transition and refractory metals will be fabricated by combinatorial magnetron sputtering and tested by high-quality high-throughput methods with respect to electrocatalytic activity and stability. Identified HEA compositions which show both properties will be fabricated as homogeneous samples on which strain effects on electrocatalysis will be studied by applying intrinsic and extrinsic strain. By using different deposition parameters and a stress sensor chip, different levels of residual stress will be engineered in the HEA films of selected compositions. Additionally, these films will be strained using external bending of coated Si micro-cantilevers. These strained films will be assessed by advanced electrochemical methods, where scanning electrochemical cell microscopy will be coupled with the strain-inducing cantilever chip.

• DFG Programme: Research Grants