High-Throughput Experimentation Platform for Hydroxide Electrodeposition and Electrochemical Evaluation of Electrocatalysts

The performance of catalysts in chemical manufacturing, energy conversion, and environmental remediation can help realize a sustainable society. However, designing efficient catalysts remains a significant challenge. Herein, we report a high-throughput screening system for hydroxide electrocatalysts that integrates hydroxide electrodeposition-based synthesis with electrochemical evaluation. It combines three concepts: standardization of the synthesis-and-evaluation workflow through electrodeposition, miniaturization using screen-printed electrodes in a 96-well microplate format, and parallelization using a home-built 32-channel potentiostat system. Reproducibility tests showed good agreement among the channels under identical conditions, and the condition-dependent performance differences could be stably captured even when the channels were assigned different electrodeposition potentials and deposition times. As a demonstration, 96 conditions defined by the Ni/Fe ratio, supporting electrolyte fraction, electrodeposition potential, and deposition time were screened for Ni–Fe hydroxide electrocatalysts toward the oxygen evolution reaction (OER). Heat-map analysis, complemented by decision-tree analysis, indicated that the Ni/Fe ratio accounted for the broadest performance differences within the investigated Ni–Fe hydroxide dataset, while synthesis-process factors further differentiated performance within individual compositional regions. These results show that, although the composition-centered high-throughput screening is effective, the incorporation of catalyst synthesis conditions is also important for identifying low-overpotential conditions and further optimizing electrocatalytic performance. The present system provides a practical platform for high-throughput electrocatalyst discovery in a coupled space of composition and synthesis process conditions.