Long‐Range SECCM Enables High‐Throughput Electrochemical Screening of High Entropy Alloy Electrocatalysts at Up‐To‐Industrial Current Densities

• Published in: Small methods Vol. 8; no. 7; pp. e2301284 - n/a
• Main Authors: Tetteh, Emmanuel Batsa, Krysiak, Olga A., Savan, Alan, Kim, Moonjoo, Zerdoumi, Ridha, Chung, Taek Dong, Ludwig, Alfred, Schuhmann, Wolfgang
• Format: Journal Article
• Language: English
• Published: Germany 01.07.2024
• Subjects: complex solid solution; high entropy alloy; high‐throughput electrochemistry; hydrogen evolution reaction; scanning electrochemical cell microscopy; SECCM; high entropy alloy; SECCM; scanning electrochemical cell microscopy; complex solid solution; high‐throughput electrochemistry; hydrogen evolution reaction
• ISSN: 2366-9608; 2366-9608
• DOI: 10.1002/smtd.202301284

High‐entropy alloys (HEAs), especially in the form of compositional complex solid solutions (CCSS), have gained attention in the field of electrocatalysis. However, exploring their vast composition space concerning their electrocatalytic properties imposes significant challenges. Scanning electrochemical cell microscopy (SECCM) offers high‐speed electrochemical analysis on surface areas with a lateral resolution down to tens of nm. However, high‐precision piezo positioners often used for the motion of the tip limit the area of SECCM scans to the motion range of the piezo positioners which is typically a few tens of microns. To bridge this experimental gap, the study proposes a long‐range SECCM system with a rapid gas‐exchange environmental cell for high‐throughput electrochemical characterization of 100 mm diameter HEA thin‐film material libraries (ML) obtained by combinatorial co‐sputtering. Due to the gas–liquid interface at the positioned SECCM droplet on the sample, high‐throughput evaluation under industrial current density conditions becomes feasible. This allows the direct correlation between electrocatalytic activity and material composition with high statistical reliability. The multidimensional data obtained accelerates materials discovery, development, and optimization. A long‐range scanning electrochemical cell microscopy setup equipped with a rapid gas exchange environmental cell is developed for the high‐throughput screening of high entropy alloy materials libraries at industrial current densities to generate statistically reliable multidimensional composition – electrochemical data which is easily applicable for machine learning and artificial intelligence (AI) electrocatalyst discovery projects.