Microkinetic Modeling of the Oxygen Evolution Reaction (OER) on Hydrous Iridium Oxide during Dynamic Operation

摘要

In an energy system which is based on intermittent renewable sources, efficient energy storage and conversion technologies are needed. Proton exchange membrane (PEM) electrolysis is a promising technology for the storage of electrical energy in the form of hydrogen. In PEM electrolyzers, the oxygen evolution reaction (OER) is seen as the bottleneck due to its high overpotential. To enhance the overall performance, highly active but stable OER catalysts are essential. Oxidized iridium shows good activity for the OER and is more stable compared to other materials such as ruthenium oxide. It has been shown that electrochemically grown hydrous iridium oxide is particularly favorable. A better understanding of the changes of its complex surface structure and chemistry during dynamic operations is crucial for practical applications and for obtaining deep insights in factors that affect its activity and stability.