Limitations and prospects
Proton Exchange Membrane water electrolysis

A superficial analysis of the situation might suggest that available reserves and the price of iridium (approximately €130/kg ^-1 in 2025) will prevent PEM technology from developing on a GW scale. In fact, electrochemistry is essentially a science of interfaces. Significant progress has been made in recent years to significantly reduce the quantities of precious metals used. Figure 23 shows, for example, that by moving from a loading of around 2 mg.cm ⁻² (a typical value for the first applications...