Enabling Low Iridium Loadings and Reduced Catalyst Material Cost for PEM Water Electrolyzers Via Composite Anode Design with Conductive Additive

Herein, we present the successful implementation of a composite anode using a conductive additive to enable low iridium (Ir) loadings for PEMWE while maintaining high-performance operation. We use platinum (Pt) black as the conductive additive given its high electrical conductivity, high stability, and a price currently one-fifth that of Ir. Using a high loading of Pt black conductive additive allowed for retained electrode thickness, good dispersion of Ir particles, and drastically decreased sheet resistance at low Ir loadings of 0.10 mg Ir cm -2 . Compared to a standard Ir oxide anode with high, commercially relevant Ir loading, a composite anode with a low loading of 0.10 mg Ir cm -2 achieved an equal current density performance at 1.8 V, translating to a 95% reduction in loading and 80% cost reduction of the anode catalyst materials.