3DIr4E: Three-Dimensional low Ir loading anodes For proton exchange membrane water Electrolyzers

Proton exchange membrane (PEM) water electrolyzers hold great significance for renewable energy storage and conversion.

However, the oxygen evolution reaction (OER) at the anode has intrinsically sluggish kinetics due to the involvement of multiple

proton-coupled electron transfer steps, which is one of the main roadblocks that hinder the practical application of PEM water

electrolyzers. Thus, highly active, cost-effective, and durable electrocatalysts are indispensable for lowering the high kinetic barrier of

OER to achieve boosted reaction kinetics, so that to improve the overall device efficiency and decrease the applied voltage. To date,

only Iridium (Ir) based materials possess adequate corrosion resistance to meet the harsh acidic and oxidative environment of the

PEM electrolyzers. Unfortunately, their high degree of scarcity and relatively low OER activity greatly hinder their industrial mass

applications. Therefore, the establishment of new strategies for catalyst electrode design and optimization to minimize the Ir metal

content while preserving a high activity and stability of OER is of great significance for PEM electrolyzers. Herein, the 3DIr4PEMWE

project aims to develop a 3D ordered anode design based on 1D IrO2 nanostructure arrays decorated with atomically dispersed Ru

and Sr single atoms catalysts (denoted Ru-Sr doped IrO2). This unique architecture can effectively circumvent the drawbacks of the

electrodes based on ultrafine particulate catalysts, including the activity loss due to the low catalyst utilization, and the activity

decline owing to particle dissolution and aggregation during the operation, thus simultaneously improved Iridium mass activity,

structural stability and mechanical strength will be achieved for the oxygen electrodes during operation. We believe the EU-funded

3DIr4PEMWE project will accelerate the industrialization of PEM water electrolyzer technology and realize the aspiring hydrogen energy society as soon as possible