Recycling Iridium and Platinum from End-of-Life Technologies: A 2050 Material-Flow Analysis

Proton exchange membrane (PEM) electrolyzers and fuel cells could substantially increase demand for iridium (Ir) and platinum (Pt), two platinum-group metals (PGMs) with concentrated primary supply chains. This study evaluates secondary Ir and Pt supply from end-of-life PEM technologies using a scenario-based material-flow analysis for global and U.S. markets from 2020 to 2050. Annual metal demand is estimated from U.S. Department of Energy annual PEM manufactured-capacity inputs, which include new and replacement systems, and from catalyst loading rates. Secondary supply is estimated using distributed lifetimes, collection efficiency, technical recovery efficiency, recycling delay, loss accounting, remaining primary requirement, and surplus. Under the central practical case, recovered Ir supplies 16.9% of global and 3.8% of U.S. PEM electrolyzer Ir demand in 2050. Recovered PEM electrolyzer Pt supplies 32.2% of global and 7.3% of U.S. demand, while recovered PEM fuel-cell Pt supplies 75.1% of global and 51.2% of U.S. demand. Sensitivity and uncertainty results show that recovery outcomes depend strongly on collection performance, recycling delay, technical recovery, catalyst loading, and capacity-input assumptions. PEM recycling can reduce future primary PGM requirements, especially for Pt, but cannot eliminate primary Ir demand during rapid PEM electrolyzer scale-up.