Towards selective Ir/IrO2 electrochemical dissolution of Ir-based electrocatalysts for enhanced proton exchange membrane water electrolyzer sustainability

Electrocatalysts containing Ir are commonly used in energy conversion devices such as proton exchange membrane water electrolyzers (PEMWEs). However, the scarcity and high cost of Ir hinder their large-scale use. Therefore, there is a need for advanced Ir recycling schemes when scaling up PEMWE technology. Prior work on Pt-IrO 2 /C nanocomposite catalysts indicates that IrO 2 has limited resistance to electrochemical degradation. Here, we built upon this observation to explore the selective dissolution of Ir/IrO 2 compared to Pt, using a scanning flow cell coupled to inductively coupled plasma mass spectrometry (SFC ICP-MS). We show that IrO 2 can even be selectively dissolved using a simple two-electrode setup. These findings are not only of fundamental interest for catalyst design but also highlight a potential pathway of electrochemically induced Ir recycling and regeneration strategies. • Investigation of bifunctional Pt-Ir/C and Pt-IrO 2 /C OER electrocatalysts. • Treatment protocol influences the respective dissolution rates of Pt and Ir. • Selective Ir dissolution in OER electrocatalysts. • Proof-of-concept demonstration for Ir recycling.