Ir Strangelove, or How to Learn to Stop Worrying and Love the PEM Water Electrolysis
Cortney Mittelsteadt, Esben Lauge Sørensen, Qingying Jia
Abstract
Proton exchange membrane water electrolyzers (PEMWEs) have emerged as one of the most promising technologies with inherent advantages for the coming hydrogen economy. However, the large amount of iridium (Ir) used in current PEMWEs versus the limited global Ir resources has been widely considered as an impediment to large-scale and sustainable deployment of PEMWEs. Herein, we argue that the demand of Ir for the PEMWE application can be substantially reduced to balance the Ir supply. This can be achieved by combining the increase in current density during PEMWE operation and reduction in Ir loading with the implementation of Ir recycling. Furthermore, platinum can serve as a viable catalyst alternative to Ir for the PEMWE application with acceptable cost compensation. We therefore anticipate that PEMWEs will be the major technology for green hydrogen production.