aem vs pem: iridium calculator

PEM electrolysers use iridium, a scarce platinum-group metal, on the anode. AEM electrolysers can run without it. Enter a capacity to see the iridium a PEM installation needs at the average loadings published by IRENA, and compare it with CRM-free AEM.

We do not set a default price – iridium prices move a lot. Use a current quote from your metals supplier.

PEM, typical loading today (1.3 g Ir/kW)

1.3 kg

PEM, IRENA future target (0.4 g Ir/kW)

0.4 kg

AEM with CRM-free OXYGN / H2GN electrodes

0 kg

no iridium, no platinum-group metals

Indicative catalyst-metal estimate only, based on the average values in IRENA (2020), Table 7. Real loadings depend on the manufacturer, current density and cell design. This is not a system cost, a price or a CENmat quote.

aem vs pem at a glance

PEM electrolysisAEM electrolysis (CENmat)
Anode catalystIridium-based; about 1.3 g Ir/kW today, 0.4 g/kW targeted (IRENA 2020, Table 7). CENmat's OXYGN (PEM) reduces iridium loading to about 0.2 mg/cm².OXYGN (AEM): CRM-free oxygen-evolution catalyst, no iridium.
Cathode catalystPlatinum; about 0.5 g Pt/kW today, 0.1 g/kW targeted (IRENA 2020, Table 7).H2GN: CRM-free hydrogen-evolution catalyst.
Membrane / ionomerPerfluorosulfonic acid (PFSA) membranes are standard (IRENA 2020, Chapter 2).AionFLX™: PFAS-free, fluorine-free anion-exchange membranes with matched ionomer.
Supply constraintCurrent iridium and platinum production supports an estimated 3–7.5 GW of PEM manufacturing per year, versus around 100 GW/year needed by 2030 (IRENA 2020).IRENA notes that AEM electrolysers do not need scarce materials in the first place.
CENmat offerOXYGN (PEM) ultra-low-iridium catalyst.HYScale stacks and systems (roughly 0.5–1 MW class), AionFLX™ membranes and ionomers, OXYGN and H2GN electrodes.

request a tailored estimate

Want numbers for your own project – capacity, operating profile and the materials you would qualify? Send us a few details and we will prepare a tailored comparison personally. Prices on request.

We reply personally. Prices on request. Fields marked * are required.

sources

  1. IRENA (2020), Green Hydrogen Cost Reduction: Scaling up Electrolysers to Meet the 1.5 °C Climate Goal, International Renewable Energy Agency, Abu Dhabi – Table 7 (iridium and platinum loading for PEM electrolysers, p. 70); Chapter 2 (PEM membranes); key findings on iridium/platinum supply.
  2. CENmat product information: OXYGN (PEM), OXYGN (AEM), H2GN, AionFLX™, HYScale.