Electron‐Rich Platinum Atoms in Lattice of Nickel‐Iron Layered Double Hydroxide Enhance Seawater Electrolysis

Why It Matters

The breakthrough dramatically lowers energy input for seawater hydrogen production, making large‑scale, low‑cost green H₂ more attainable.

Key Takeaways

• PtNiFe-D15 contains 0.98 wt% platinum.
• Overpotential 217 mV at 1000 mA cm⁻² in seawater.
• Beats commercial 20 wt% Pt/C (489 mV) and peers.
• Electron‑rich Pt and vacant Ni sites accelerate HER steps.
• AEM electrolyzer runs 1.75 V at 1000 mA cm⁻².

Pulse Analysis

Seawater electrolysis promises virtually limitless hydrogen feedstock, yet the hydrogen evolution reaction (HER) in saline environments suffers from sluggish kinetics and corrosion‑induced degradation. Conventional catalysts rely on high loadings of precious metals, inflating capital costs and limiting scalability. Recent advances in layered double hydroxides (LDHs) have shown that tailoring electronic structures can unlock new reaction pathways, but achieving industrial‑grade current densities has remained elusive. By embedding trace amounts of platinum directly into the NiFe‑LDH lattice, researchers have created a catalyst that leverages both the intrinsic activity of Pt and the abundant, inexpensive NiFe matrix.

The PtNiFe‑D15 material exhibits a unique electronic configuration: oxygen vacancies generate empty Ni 3d orbitals, while the doped Pt atoms become electron‑rich, facilitating water adsorption and weakening O‑H bonds. This synergistic effect translates into an overpotential of just 217 mV at 1000 mA cm⁻² in alkaline seawater, a performance gap of over 250 mV compared with commercial 20 wt% Pt/C. Moreover, the catalyst maintains stable operation over extended periods, indicating resistance to chloride‑induced poisoning that typically plagues seawater electrolyzers. The low platinum content (0.98 wt%) dramatically reduces material costs without sacrificing activity.

When deployed as the cathode in an anion‑exchange‑membrane water electrolyzer, PtNiFe‑D15 enables the system to reach 1000 mA cm⁻² at 1.75 V, surpassing most reported seawater electrolyzer benchmarks. This voltage reduction directly cuts electricity consumption, improving the levelized cost of hydrogen. The approach also aligns with emerging circular‑economy goals, as the catalyst can be synthesized from readily available precursors and potentially recycled. As the industry pushes toward gigawatt‑scale green hydrogen hubs, such low‑loading, high‑performance catalysts could be pivotal in bridging the gap between laboratory breakthroughs and commercial deployment.