Microscale Combinatorial Libraries for the Discovery of High‐Entropy Materials. Issue 9 (5th January 2023)

• Record Type: Journal Article
• Authors: Banko, Lars; Tetteh, Emmanuel Batsa; Kostka, Aleksander; Piotrowiak, Tobias Horst; Krysiak, Olga Anna; Hagemann, Ulrich; Andronescu, Corina; Schuhmann, Wolfgang; Ludwig, Alfred
• Is Part Of: Advanced materials. Volume 35:Issue 9(2023)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2023-01-05
• Subjects: combinatorial electrocatalyst discovery -- composition space -- electrocatalysis -- high‐entropy materials -- microlibraries; Materials -- Periodicals; Chemical vapor deposition -- Periodicals; 620.11
• DOI: 10.1002/adma.202207635
• Languages: English
• ISSNs: 0935-9648

Abstract

Abstract: Polyelemental material systems, specifically high‐entropy alloys, promise unprecedented properties. Due to almost unlimited combinatorial possibilities, their exploration and exploitation is hard. This challenge is addressed by co‐sputtering combined with shadow masking to produce a multitude of microscale combinatorial libraries in one deposition process. These thin‐film composition spreads on the microscale cover unprecedented compositional ranges of high‐entropy alloy systems and enable high‐throughput characterization of thousands of compositions for electrocatalytic energy conversion reactions using nanoscale scanning electrochemical cell microscopy. The exemplary exploration of the composition space of two high‐entropy alloy systems provides electrocatalytic activity maps for hydrogen evolution and oxygen evolution as well as oxygen reduction reactions. Activity optima in the system Ru–Rh–Pd–Ir–Pt are identified, and active noble‐metal lean compositions in the system Co–Ni–Mo–Pd–Pt are discovered. This illustrates that the proposed microlibraries are a holistic discovery platform to master the multidimensionality challenge of polyelemental systems. Abstract : Microscale combinatorial libraries are introduced as a new method for exploration of polyelemental material systems. Composition gradients of quinary material systems are produced and characterized for crystal properties and electrocatalytic activity. The small dimensions of microscale combinatorial libraries enable efficient screening of thousands of compositions. Highly active electrocatalysts are identified in the systems Ru–Rh–Pd–Ir–Pt and Co–Ni–Mo–Pd–Pt.