Built to last: stainless steel in H2 generation

While hydrogen makes headlines the electrolyzer market continues to evolve. From a supplier of high-cost equipment for narrow industrial applications, the sector’s key metrics now involve higher volume sales, a broader customer base, longer operating lifetimes, and – most of all – falling unit costs. All driven by the global energy transition towards clean hydrogen production as both fuel and feedstock. The once-niche industry is now truly mass-market.

Of course, with change comes challenges. PEM electrolyzers operate under harsh conditions demanding of highly durable Porous Transport Layers (PTLs). These are often made of titanium, an effective but costly material. And while platinum coatings can improve performance and lifetime, they add to the expense. In AEM electrolyzers, research is exploring materials such as nickel and stainless steel to find the right balance of robustness, scalability, and cost.

In recent years, stainless steel has emerged to address this balance - with several advantages for todays electrolyzer customers. In this article, we'll demonstrate how this low-cust but verstalie material enables hydrogen producers to not only lower costs, but produce at scale. Without costs scaling at the same time.

Electrolyzers in flux: the changing role of H2
Hydrogen is no longer just an industrial gas. For applications in fossil stalwarts, like aviation and ocean freight, it's a core feedstock of sustainable fuels. For other hard-to-abate industries like steel and plastics, it provides cleaner, greener heat and process chemistry.

And when produced with energy from renewable sources - like wind and solar - it's a truly green input. With financial benefits to everything from carbon credits, to incentives, and even grants.

This means the drive for Net Zero by 2050 - realistsic or not - is creating huge opportunities for porducers of clean hydrogen. One liter of SAF (Sustainable Aviation Fuel) commands a market price 3-5x higher than fossil-based JET-A. While ammonia production, key to the synthetic fertilizers that keep the world's food growing, uses vast quantities of the gas. But has yet to decarbonize. And that means equally high demand for the electrolyzers that produce it.

PEM and AEM: two distinct use cases
The electrolyzer market comes in two flavors: Proton Exchange Membrane (splitting feedstock into oxygen, electrons, and protons before combining the latter pair into hydrogen), and Anion Exchange Membrane (where the split is hydroxide ions and hydrogen, with oxygen as the product). They're not merely two methods - they're entirely different chemistries.

Core to both is the Porous Transport Layer, a spongelike felt of microscale fibers performing multiple roles. The PTL conveys the reactant (water), removes the outputs (hydrogen and oxygen gas), conducts electrons, an dprovides structural strength to the delicate AEM or PEM membrane. The key difference: packed with mobile protons, conditions in a PEM electrolyzer are strongly acidic. Hence the need for pricey titanium in the PTL. Within an AEM, though, free anions create the opposite. An alkaline environment.

The cost advantages of SS in PTLs
With the low-alkaline environment making chromium dissolution (which would slowly destroy an equivalent PEM over time) unproblematic, stainless steel represents a balance of advantages. Resistant to corrosion, resilient amid pressure differences, and with low unit costs, a stainless steel PTL can achieve an operating lifetime of 20-80,000 hours. Plus, stainless steel is among the most recyclable materials in the industry today. Making your sustainable business process even more so - now and for the long term.

All industries evolve to suit changing conditions - and the electrolyzer market is no exception. As a material option for AEM electrolyzers, stainless steel PTLs may represent the best of all worlds for the H2 production at scale. Enabling reliable operation for not years, but decades.

Interested in learning more? Check out what we're up to at our Hydrogen Innovation Hub.