PEM electrolysis catalysts
The live pack. Screen acidic oxygen-evolution catalysts and see what each candidate does to cost per kilogram.
The problem
Green hydrogen from PEM water electrolysis needs a catalyst that drives oxygen evolution efficiently, survives acid at potential, and uses very little iridium. Those three pull against each other, and the third is a hard physical constraint: world primary iridium production is roughly seven to eight tonnes a year, as a by-product of platinum mining, so supply does not respond to demand.
The candidate space runs to millions of compositions, structures and surfaces. A laboratory can synthesise and test perhaps five to twenty a year. Almost everything that could be tried, never is.
How the pack works
- Relaxation and surface generation with machine-learned interatomic potentials, fine-tuned for acidic oxide surfaces rather than general bulk crystals.
- OH*, O* and OOH* adsorption energies across candidate sites, converted into a thermodynamic overpotential descriptor with uncertainty.
- A dissolution-risk estimate under acidic OER conditions, because stability is what actually kills PEM catalysts in service.
- Propagation through a PEM cell and system model to kWh/kg H2, iridium g/kW and levelised cost, so candidates rank on the commercial objective.
- Candidate space
- Compositions, structures and surfaces of acidic oxide catalysts
- What one experiment costs
- Synthesis and electrochemical testing — 2–3 months per batch
- Predictor
- Fine-tuned machine-learned interatomic potentials
- Decides on
- Levelised cost of hydrogen (€/kg)
Everything in this pack
Capabilities, free tools and the published method.
OER activity screening →
Relaxation, slabs, adsorption and the overpotential descriptor.
Acidic stability →
Dissolution risk under acidic oxygen evolution.
Cost-per-kilogram closure →
Properties propagated to kWh/kg, g/kW and LCOH.
Substitution series →
A whole composition space, ranked on a cost frontier.
LCOH calculator →
Free. Catalyst performance to cost per kilogram, no account.
Iridium intensity calculator →
Free. Loading and power density to g/kW and tonnes per GW.
Overpotential converter →
Free. Tafel extrapolation so published claims become comparable.
Guide: evaluating a low-iridium claim →
What to check before believing a paper or a supplier pitch.
Guide: what 100 mV actually costs →
Translating activity into euros per kilogram.
Method and validity limits →
The cell model, the cost model, and where both stop being valid.
Questions
Is this a replacement for DFT?
No. It is the screening layer that decides which candidates deserve converged DFT or a laboratory slot. Triage, not a verdict.
How much iridium reduction is meaningful?
Ask for grams per kilowatt rather than a percentage — percentages need a baseline and baselines vary enormously. Widely discussed targets for large-scale deployment sit well below 0.1 g/kW.
What if my composition is unusual?
If it falls outside the validated domain the run is refused with an explanation rather than returning a number we cannot defend.