SrIr_xCo_1-xO₃ as Efficient Electrocatalysts for Water Splitting Reactions to Produce Green Hydrogen

The search of efficient and stable electrocatalysts for oxygen evolution reaction (OER) in acidic electrolyte is the key to enable the commercialization of proton exchange membrane (PEM) electrolyzers and lower hydrogen production price. However, there are few choices for such electrocatalysts due to the corrosive and oxidative conditions. As the discovery of SrIrO₃ as a new type of electrocatalysts in acidic OER, we have focused on the fundamental studies of mechanism that leads to its much better acitivity (~ 1000 times more) than the commercial standard, IrO₂. Using SrIrO₃ thin films that were grown by molecular beam epitaxy as the model system, we have comprehensively investigated the surface restructuring and Sr leaching in the reaction at the atomic scale through a combination of several synchrotron X-ray scattering and spectroscopy characterizations as well as density functional theory. With learned insights, we have designed Ir less SrIrO₃-based catalysts in powders synthesized from scalable solution-based method and show that the previously in-situ electrochemically activated active phases of SrIr_xCo_1-xO₃ can be produced through ex-situ processes such as chemical leaching and ball milling. We are extending our fundamental studies to applied research for more practical applications.