Low-iridium PEM electrolysis

Electricity can split water into hydrogen and oxygen. In a PEM electrolyser, a thin membrane separates the reactions, and an iridium catalyst helps make oxygen. Iridium is scarce. Can these devices use much less of it and still make hydrogen efficiently for years, including when the power rises and falls?[1] [2]

A PEM electrolyser uses a proton-conducting membrane to separate hydrogen and oxygen production. Its acidic oxygen-producing anode favors durable iridium-based catalysts. Lower iridium loading must coexist with useful current, low voltage losses and long device life under changing power. A 2025 small-cell study reported over 10,000 hours at steady current and a separate 1,000-hour test at low loading under simulated fluctuations. These are distinct demonstrations, not a combined large-stack lifetime result.[1] [2]

Reducing the metal is not enough: the device must also retain its output and efficiency during long operation. Successful small-cell tests leave the combined low-metal, large-device and changing-power challenge open.[1] [2]

Practical translation couples catalyst-layer transport, corrosion, membrane assembly and device resistance. These demonstrations do not establish the same lifetime at low loading in a large fluctuating-power stack.[1] [2]

Each device uses only a little iridium, but building many devices adds up. Reducing the amount needed without shortening their lives could let more hydrogen-producing equipment be built from a limited metal supply.[2]

The useful resource question is how much hydrogen a quantity of iridium enables over repeated operation. Scarcity makes lower loading attractive, but deterioration and transport losses can offset the savings by shortening life or increasing electricity use. Linking catalyst design to the membrane assembly and device therefore helps determine whether a material improvement can actually ease the supply constraint on expanding hydrogen electrolysis.[1] [2]