XT iridium catalysts include unsupported oxides for the oxygen evolution reaction in PEM water electrolyzers, plus carbon-supported iridium and platinum–iridium powders. Carbon is not stable at a PEM electrolyzer anode, so the oxides are supplied without a carbon support.
Iridium oxide is used for the anode of PEM water electrolysis, where the electrolyte is acidic and strongly oxidizing. XT Iridium Ruthenium Oxide (IrRuOx) puts iridium and ruthenium in one mixed oxide, which lowers the share of iridium in the powder. It is not ruthenium-supported iridium, and it is not a mixture of separate iridium oxide and ruthenium oxide powders.
These catalysts are used at the anode of PEM water electrolyzers. They can also be used as the oxygen-evolution anode in a CO₂ electrolysis cell. The CO₂ reduction catalyst is on the cathode and is selected separately. Both are available as powders for inks and electrode development, and both can be coated into catalyst-coated membranes, electrodes, and membrane electrode assemblies.
