The platinum substitution problem

The physical problem

Europe's REPowerEU plan targets approximately 100 GW of installed electrolyser capacity by 2030^[1]. A proton-exchange-membrane (PEM) electrolyser running at commercial current densities requires roughly 0.3–0.8 g of iridium per kilowatt of capacity^[2]. Global iridium production is approximately 7 tonnes per year — a by-product of platinum refining, not an independent supply.

At 0.5 g/kW and 100 GW, the iridium requirement is 50 tonnes. The cumulative European requirement is therefore several times the entire annual global supply of iridium, in a commodity that cannot be scaled through capital expenditure because it is a by-product. Mathematically, the PEM pathway to the 2030 target is not available.

The alkaline alternative

Alkaline electrolysers use a different chemistry. They operate in hot potassium hydroxide solution instead of a proton-exchange membrane, and they do not require iridium. The classical reference electrode is Class-1 nickel — at 78 % Faradaic efficiency, acceptable but not competitive with PEM on efficiency per kilowatt.

The step-change is the addition of ruthenium-oxide (RuO₂) coating on precision nickel mesh. RuO₂ lowers the oxygen-evolution overpotential to platinum-like numbers. On ordinary Class-1 nickel the improvement is bounded by the grain-boundary chemistry of the substrate; on NP1-grade (99.99 %) nickel the improvement is nearly complete.

Fig. 1 — Faradaic efficiency at 2000 h continuous alkaline operation. Source: Prof. Ramamurty 2025 bench data.

Why ruthenium is not the iridium problem again

Global ruthenium production is approximately 30 tonnes per year — four times iridium. More importantly, the coating thickness required on NP1 mesh is roughly 4.8 µm, which at electrolyser active-area densities implies a mass ratio of ~10 g of ruthenium per MW. At 100 GW, that is 1000 kg — around 3 % of annual supply. This is a feasible deployment, not a physical impossibility.

The economics

Platinum trades at approximately USD 32 / g at time of writing; iridium at USD 150 / g; ruthenium at USD 14 / g. Add to this the fact that the NP1 nickel substrate itself trades at a purity premium versus Class-1 nickel (USD ~50 / kg versus USD ~19 / kg), and the unit-economics picture looks as follows:

• PEM stack material cost: approximately USD 1200–1800 / kW at 2025 prices.
• RuO₂/NP1 alkaline stack material cost: approximately USD 90–140 / kW.
• Differential: roughly 90 % lower raw-material cost at 98 % of Faradaic efficiency.

At 100 GW European build-out, the platinum-substitution problem is not a debate about cost curves. It is a question of which metals are available in sufficient quantity to physically deliver the hardware. PGM supply is not.

What this implies

Three consequences follow. First, 2026–2028 order books for NP1-grade mesh are likely to tighten structurally as European electrolyser manufacturers qualify second-source materials. Second, the commodity-nickel price signal (LME settlement) will be a poor proxy for precision-nickel pricing through the decade. Third, reservoir holders of NP1-grade material — with lot-level provenance and institutional custody — acquire a strategic supply-chain position that is unusually defensible.