High-throughput discovery of hydrogen evolution electrocatalysts in the complex solid solution system Co-Cr-Fe-Mo-Ni

Discovery of new electrocatalysts requires the combination of high-throughput synthesis and high-throughput screening techniques to explore the vast compositional range of compositionally complex solid solutions (CCSS). This work explores more than 1000 different compositions of the quinary CCSS system Co-Cr-Fe-Mo-Ni as electrocatalysts for the hydrogen evolution reaction (HER). Thin-film material libraries prepared by magnetron co-sputtering are characterized, and their electrocatalytic activity towards hydrogen formation via water electrolysis in alkaline electrolyte is evaluated using a scanning droplet cell (SDC). Using this high-throughput approach, we identified 349 compositions in the Co-Cr-Fe-Mo-Ni space with similar or higher electrocatalytic activity than Co35Cr15Fe20Mo10Ni20, which was recently reported as a HER catalyst. The highest activity from the explored Co-Cr-Fe-Mo-Ni CCSS system was found for Co56Cr8Fe19Mo7Ni10.

Automated summary

The study explores compositionally complex solid solutions as electrocatalysts for the hydrogen evolution reaction using high-throughput synthesis and screening techniques. Among over 1000 different compositions, 349 compositions with similar or higher activity were identified, with Co56Cr8Fe19Mo7Ni10 showing the highest activity.