Short‐Range‐Engineered Nd‐Doped IrOx Enables Oxide Path Mechanism for High‐Performance PEM Water Electrolysis

Why It Matters

The catalyst cuts iridium usage while delivering record activity and durability, directly lowering the capital expense of PEM electrolysis and accelerating the green hydrogen economy.

Key Takeaways

• Nd-doping tailors Ir–Ir distances for O–O coupling.
• Overpotential reduced to 254 mV at 10 mA cm⁻².
• 0.5 mg Ir cm⁻² anode reaches 4 A cm⁻².
• Stability exceeds 1000 h at 1 A cm⁻².
• Enables lower iridium usage, cutting green hydrogen cost.

Pulse Analysis

Proton‑exchange‑membrane water electrolysis (PEMWE) is the leading technology for large‑scale green hydrogen because it operates at high current density and produces pure gas. However, the oxygen‑evolution reaction (OER) at the anode still relies on iridium‑based catalysts, and iridium’s scarcity drives up capital costs. Researchers have therefore been searching for catalyst architectures that deliver high activity while minimizing iridium loading, without sacrificing long‑term durability under acidic conditions.

The recent study introduces neodymium‑doped amorphous IrOx (Nd‑IrOx), a catalyst engineered at the short‑range structural level. Incorporating Nd³⁺ ions distorts the IrO₆ octahedral network, shortening Ir‑Ir distances and stabilizing surface OH groups, which together activate the oxide‑path mechanism (OPM) for direct *O‑O* coupling. This structural tuning lowers the kinetic barrier for OER, delivering an overpotential of only 254 mV at 10 mA cm⁻², a performance previously unattainable with comparable iridium loadings.

In practical PEMWE cells, the Nd‑IrOx anode achieves 4 A cm⁻² at 1.9 V with an iridium loading of just 0.5 mg Ir cm⁻², and it maintains stable operation for more than 1000 hours at 1 A cm⁻². These figures translate into a substantial reduction in catalyst cost and a longer service life, directly impacting the economics of green hydrogen production. The work demonstrates that short‑range engineering can reconcile activity‑stability trade‑offs, opening a pathway for next‑generation, low‑iridium OER catalysts across the renewable‑energy sector.