On stage among major elec­trolyz­er man­u­fac­tur­ers and pol­i­cy experts, Elli­nor Ehrn­berg, Pres­i­dent of Smoltek Hydro­gen, offered a refresh­ing­ly direct answer: “start with the atoms.”

The hidden bottleneck: Iridium

“At the very heart of a PEM elec­trolyz­er lies irid­i­um. That’s where the mag­ic hap­pens. When a water mol­e­cule meets irid­i­um, is splits into oxy­gen and hydro­gen. This process can be made repeat­ed­ly at an afford­able cost, as long as we just pour in more water. But irid­i­um is dif­fer­ent sto­ry; it is one of the rarest met­als on Earth, more expen­sive than gold — and we can’t pro­duce so much more of it,” Elli­nor Ehrn­berg explained. 

Every pro­ton exchange mem­brane (PEM) elec­trolyz­er depends on irid­i­um as its cat­a­lyst to split water into hydro­gen and oxy­gen. The prob­lem? Only 7–9 tons of irid­i­um are mined glob­al­ly per year, most­ly in South Africa and Rus­sia, and pro­duc­tion can­not be scaled up. This makes the world’s green hydro­gen ambi­tions severe­ly constrained. 

“At today’s small hydro­gen vol­umes, using 2 mil­ligrams per square cen­time­ter is man­age­able. But if we want to scale to hun­dreds of gigawatts, it sim­ply isn’t pos­si­ble. The lim­it­ed sup­ply of irid­i­um will stop the hydro­gen econ­o­my before it even starts—unless we use it more effi­cient­ly,” Elli­nor Ehrn­berg continued.

A 95% reduction in iridium use is possible

Smoltek Hydrogen’s answer is a nan­otech­nol­o­gy break­through that dra­mat­i­cal­ly extends the life of this pre­cious resource. Using a pro­pri­etary Porous Trans­port Elec­trode (PTE) built with cor­ro­sion pro­tect­ed car­bon nanos­truc­tures the com­pa­ny has increased the active sur­face area of the cat­a­lyst lay­er by up to 30 times.

This allows irid­i­um atoms to be applied pre­cise­ly where they are needed—and nowhere else. The result is a 95% reduc­tion in irid­i­um use, down to just 0.1 mil­ligram per square cen­time­ter, while main­tain­ing full per­for­mance and durability.

“We can make the elec­trolyz­er up to three times more com­pact. Instead of three stacks, you only need one. That’s how we make green hydro­gen tru­ly scal­able,” Elli­nor Ehrn­berg noted.

The cost sav­ings are just as strik­ing. “Using only five per­cent of the irid­i­um saves sev­er­al thou­sand euros per square meter of stack area. That’s real money—and real scal­a­bil­i­ty”, she said. 

In sum­ma­ry: Smoltek Hydrogen’s PTE tech­nol­o­gy enables small­er, more cost-effi­cient elec­trolyz­ers that require sig­nif­i­cant­ly less irid­i­um. This inno­va­tion allows for a more com­pact stack design, reduc­ing both sys­tem size and over­all cost — sav­ing thou­sands of euros per square meter of stack area.

Building the future through collaboration and partnerships

But who will man­u­fac­ture these PEM elec­trolyz­ers that will unlock the green hydro­gen economy?

Elli­nor Ehrn­berg empha­sized that no sin­gle com­pa­ny can solve the mate­ri­als chal­lenge alone “Col­lab­o­ra­tion is the only way to make such pre­ci­sion scal­able. We are for­tu­nate to work with part­ners who share our vision of build­ing a sus­tain­able hydro­gen econ­o­my through smarter mate­ri­als engineering.” 

Today Smoltek Hydro­gen has estab­lished indus­tri­al part­ner­ships with Her­aeus Pre­cious Met­als, AGC Plas­ma Tech­nolo­gies, Spark Nano, and Impact Coat­ings, along­side oth­er undis­closed glob­al tech­nol­o­gy lead­ers. These part­ners and cus­tomers are help­ing Smoltek move from pro­to­type to pro­duc­tion-scale systems.

“We build nanos­truc­tures atom by atom—from tita­ni­um, plat­inum, and iridium—and we must co-devel­op each lay­er with part­ners across the val­ue chain,” she added.

Efficiency and circularity: The next frontier 

Beyond tech­no­log­i­cal effi­cien­cy, Elli­nor Ehrn­berg believes resource cir­cu­lar­i­ty will define the future of hydro­gen. “We have to use much less iridium—and recy­cle it,” she said. “Effi­cien­cy and cir­cu­lar­i­ty are key if we want to future-proof the hydro­gen economy.”

In oth­er words, inno­va­tion can­not come at the expense of sus­tain­abil­i­ty. Every improve­ment must serve both the eco­nom­ics and the ecol­o­gy of green hydro­gen production.

While the con­ver­sa­tion around hydro­gen often focus­es on scale—more elec­trolyz­ers, larg­er plants, big­ger num­bers— Elli­nor Ehrn­berg cau­tioned against equat­ing vol­ume with progress.

“Scal­ing green hydro­gen isn’t just about pro­duc­ing more—it’s about pro­duc­ing smarter.
We need to rethink the mate­ri­als, the man­u­fac­tur­ing, and even the mind­sets that built yesterday’s indus­try. Every atom count,” she said.

That sen­ti­ment cap­tured the spir­it of this year’s Hydro­gen Tech­nol­o­gy World Expo: that break­throughs in mate­ri­als sci­ence, not just pol­i­cy or fund­ing, will deter­mine how fast the hydro­gen tran­si­tion can tru­ly accelerate.

Smoltek’s role in the hydrogen evolution

From its base in Gothen­burg, Smoltek Hydro­gen is demon­strat­ing how deep mate­ri­als exper­tise can unlock the next era of renew­able ener­gy. By com­bin­ing nanos­truc­tured engi­neer­ing with indus­tri­al part­ner­ships, the com­pa­ny is help­ing make green hydro­gen pro­duc­tion both cost-effec­tive and resource responsible.

Smoltek’s tech­nol­o­gy direct­ly address­es one of the hydro­gen industry’s most crit­i­cal pain points—the irid­i­um bottleneck—and in doing so, it opens the door to the mass deploy­ment of fos­sil-free hydro­gen need­ed to decar­bonize heavy indus­try, trans­porta­tion, and ener­gy storage.

As the ener­gy world piv­ots from promise to imple­men­ta­tion, Smoltek’s mes­sage from Ham­burg was clear: “We can’t cre­ate more irid­i­um, but we can use what we have infi­nite­ly bet­ter. And that’s how we make the hydro­gen econ­o­my tru­ly sus­tain­able,” Elli­nor Ehrn­berg concluded.

Before leav­ing the stage, she remind­ed the hydro­gen com­mu­ni­ty: “So, please — stop putting thick lay­ers of irid­i­um on mem­branes. Use thin, effi­cient lay­ers on elec­trodes instead. Because every atom counts.”

And with these clos­ing words we leave Ham­burg, for this time. 

---

Key takeaways from Hydrogen Technology World Expo 2025 in Hamburg

• Nan­otech­nol­o­gy is the enabler: Irid­i­um scarci­ty can no longer be afford­ed to over­look. Smoltek’s PTE uses 95% less irid­i­um while main­tain­ing per­for­mance and durability.
• Com­pact and cost-effec­tive: Up to three times small­er stack foot­print, cut­ting sys­tem costs dramatically.
• Strate­gic part­ner­ships: Col­lab­o­ra­tion with major indus­tri­al play­ers ensures scal­able, high-pre­ci­sion manufacturing.
• Sus­tain­abil­i­ty through effi­cien­cy: Reduced crit­i­cal mate­r­i­al use and poten­tial for recy­cling are essen­tial for long-term growth.