Green hydrogen powered by renewables cannot be fully realized without attaining cost parity with the incumbent technology of steam reformed natural gas. Reaching hydrogen costs of $1-$2 USD per kg of hydrogen with proton exchange membrane (PEM) water electrolysis requires substantial system cost reductions.

A considerable fraction of a PEM electrolysis stack’s cost derives from precious metals such as platinum and iridium, used for corrosion protection and catalysis, respectively.  Platinum and iridium costs have roughly doubled since the end of 2024, increasing the urgency of reducing the content of these metals in PEM systems. 

In this talk, a route to reduction of platinum and iridium content in PEM electrolysis cells via engineering of the porous transport layer (PTL) will be discussed.  Iridium in the catalyst layer can be reduced by engineering the porosity, pore size, and roughness of the PTL to optimize contact with the anode.  In the case of platinum, advanced thermochemical processing is used to grow titanium compounds directly on bare titanium, fully protecting the flowfield side of the PTL from corrosion to cut Pt content 50%.. Together, these innovations demonstrate how targeted materials and component engineering can offer a compelling strategy for decreasing electrolyzer costs, improving supply chain resilience, and advancing the commercialization of affordable, large-scale green hydrogen production.