A Critical Evaluation of a Self-Driving Laboratory for the Optimization of Electrodeposited Earth-Abundant Mixed-Metal Oxide Catalysts for the Oxygen Evolution Reaction (OER)

Abstract: This work highlights the potential of earth-abundant mixed-metal oxide catalysts for the acid-based oxygen evolution reaction. These catalysts offer numerous combinations of metal-centre compositions, which can enhance catalytic activity and stability compared to precious-metal-based catalysts commonly used today. Despite substantial research in this field, there is a need for new methods and approaches to accelerate the exploration of these materials. In this study, we present a comprehensive approach to designing, developing, and implementing a self-driving laboratory to optimize the electrodeposition synthesis of amorphous mixed-metal oxide catalysts for the acidic oxygen evolution reaction. We particularly emphasize the development of methodologies to address experimental variability. We investigate crucial parameters and considerations when transitioning from manual bench-top synthesis and evaluation to automation and machine learning guided optimization. We address both experimental and optimization algorithm considerations in the presence of experimental variability. To illustrate our approach, we demonstrate the optimization of CoFeMnPbOx electrodeposited catalyst materials through multiple campaigns. Our results highlight considerations for optimizing overpotential and stability based on the outcomes of our experiments.