Suchergebnisse

Complex solid solutions ("high entropy alloys"), comprising five or more principal elements, promise a paradigm change in electrocatalysis due to the availability of millions of different active sites with unique arrangements of multiple elements directly neighbouring a binding site. Thus, strong electronic and geometric effects are induced, which are known as effective tools to tune activity. With the example of the oxygen reduction reaction, we show that by utilising a data‐driven discovery cycle, the multidimensionality challenge raised by this catalyst class can be mastered. Iteratively refined computational models predict activity trends around which continuous composition‐spread thin‐film libraries are synthesised. High‐throughput characterisation datasets are then used as input for refinement of the model. The refined model correctly predicts activity maxima of the exemplary model system Ag‐Ir‐Pd‐Pt‐Ru. The method can identify optimal complex‐solid‐solution materials for electrocatalytic reactions in an unprecedented manner. ; ZGH is acknowledged for using XRD, AFM, EDX and APT. W.S. acknowledges funding from Deutsche Forschungsgemeinschaft (DFG) under Germany's Excellence Strategy (EXC 2033‐390677874–RESOLV) and from the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation programme (grant agreement CasCat.[833408] A.L., A.S., and B.X. acknowledge funding from DFG projects LU1175/22‐1 and LU1175/26‐1, V.S. acknowledges a scholarship from IMPRS SurMAT. J.P. acknowledges support from the Danish Ministry of Higher Education and Science (Structure of Materials in Real Time (SMART) grant). T.B., J.P, C.C., and J.R. thank the Danish National Research Foundation Center for High‐Entropy Alloy Catalysis (CHEAC) DNRF‐149, and from research grant 9455 from the VILLUM FONDEN. Open access funding enabled and organized by Projekt DEAL.

Active, selective and stable catalysts are imperative for sustainable energy conversion, and engineering materials with such properties are highly desired. High-entropy alloys (HEAs) offer a vast compositional space for tuning such properties. Too vast, however, to traverse without the proper tools. Here, we report the use of Bayesian optimization on a model based on density functional theory (DFT) to predict the most active compositions for the electrochemical oxygen reduction reaction (ORR) with the least possible number of sampled compositions for the two HEAs Ag-Ir-Pd-Pt-Ru and Ir-Pd-Pt-Rh-Ru. The discovered optima are then scrutinized with DFT and subjected to experimental validation where optimal catalytic activities are verified for Ag–Pd, Ir–Pt, and Pd–Ru binary alloys. This study offers insight into the number of experiments needed for optimizing the vast compositional space of multimetallic alloys which has been determined to be on the order of 50 for ORR on these HEAs. ; J.P., C.C., V.M., T.B., M.A., and J.R. acknowledge support from the Danish National Research Foundation Center for High Entropy Alloy Catalysis (CHEAC) DNRF-149. J.P. acknowledges support from the Danish Ministry of Higher Education and Science (Structure of Materials in Real Time (SMART) grant), T.B. acknowledges support from VILLUM FONDEN (research grant 9455), W.S. acknowledges funding from Deutsche Forschungsgemeinschaft (DFG) under Germany's Excellence Strategy (EXC 2033-390677874—RESOLV) and from the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation programme (grant agreement CasCat [833408]. A.L. and B.X. acknowledge funding from DFG project LU1175/26-1. ZGH at RUB is acknowledged for use of its experimental facilities.