Hollow Iridium-Based Catalysts for the Oxygen Evolution Reaction in Proton Exchange Membrane Water Electrolyzers

Hollow IrO2 microspheres were synthesized directly from aqueous solution using hydrated IrCl3 in presence of a porogen. This step was followed by thermal treatment in air at different temperatures to achieve the oxidation of the porogen and crystallization of IrO2. The temperature of this treatment was found to be crucial to finely tune the structural, morphological and electronic features of the synthesized materials, which has a strong impact on their electrochemical performance.