Smoltek’s groundbreaking PTE technology earns expert recognition

Smoltek has tak­en a strate­gic step by invit­ing Dr. Felix N. Büchi, an inde­pen­dent expert in pro­ton exchange mem­brane (PEM) tech­nolo­gies, to review Smoltek Hydrogen’s Porous Trans­port Elec­trode (PTE) tech­nol­o­gy. In his eval­u­a­tion, Dr. Büchi rec­og­nizes that ”Smoltek elec­trodes are a very inter­est­ing devel­op­ment for the pro­duc­tion of low irid­i­um load­ing elec­trodes for PEM elec­trolyz­ers.” His com­pre­hen­sive analy­sis pro­vides valu­able insights for fur­ther devel­op­ment. Let’s delve into the details of this excit­ing eval­u­a­tion and what it means for Smoltek’s future.

Who is Dr. Felix N. Büchi?

You might be won­der­ing who Dr. Felix N. Büchi is and why his opin­ion car­ries such weight. As a promi­nent Swiss sci­en­tist spe­cial­iz­ing in elec­tro­chem­i­cal ener­gy con­ver­sion and stor­age, Dr. Büchi is at the fore­front of fuel cell tech­nol­o­gy and elec­trolyz­er development.

As Group Head at the Elec­tro­chem­istry Lab­o­ra­to­ry at Switzerland’s pres­ti­gious Paul Scher­rer Insti­tute (PSI), Dr. Büchi focus­es on advanc­ing PEM fuel cells and PEM elec­trolyz­ers. His exper­tise is par­tic­u­lar­ly rel­e­vant in char­ac­ter­iz­ing and eval­u­at­ing porous mate­ri­als for these appli­ca­tions. His pio­neer­ing work with X‑ray imag­ing under operan­do con­di­tions has rev­o­lu­tion­ized the under­stand­ing of PEM devices’ mass trans­port and two-phase flow, lead­ing to approx­i­mate­ly 50 ded­i­cat­ed papers since 2009.

With a Ph.D. in Fun­da­men­tal Elec­tro­chem­istry from the Uni­ver­si­ty of Bern and expe­ri­ence from respect­ed insti­tu­tions like Texas A&M Uni­ver­si­ty, Dr. Büchi is rec­og­nized glob­al­ly for his exper­tise in poly­mer elec­trolytes and elec­tro­chem­i­cal systems.

The Büchi Report

Dr. Büchi’s assign­ment was to eval­u­ate Smoltek Hydrogen’s PTE tech­nol­o­gy. The result­ing doc­u­ment, ”The Büchi Report,” pro­vides an in-depth analy­sis of the technology’s per­for­mance and areas for fur­ther optimization.

While the full report con­tains con­fi­den­tial busi­ness infor­ma­tion, we’re excit­ed to share key high­lights with you. These insights demon­strate how Smoltek’s inno­va­tion address­es a crit­i­cal chal­lenge in the PEM elec­trolyz­er indus­try –  the press­ing issue of irid­i­um scarci­ty that threat­ens to con­strain the industry’s growth.

The iridium challenge

The num­bers tell a strong  sto­ry: The green hydro­gen indus­try will need 30 tons of irid­i­um annu­al­ly by 2030, while glob­al pro­duc­tion capac­i­ty is lim­it­ed to 9 tons annu­al­ly. With cur­rent irid­i­um prices around 150,000 EUR per kilo­gram, and mar­ket ana­lysts pro­ject­ing prices to reach 700,000 EUR per kilo­gram by 2030 due to the sup­ply-demand gap, reduc­ing irid­i­um usage becomes cru­cial for com­mer­cial via­bil­i­ty. With our tech­nol­o­gy, irid­i­um con­sump­tion is reduced by 95% com­pared to cur­rent levels.

Understanding PEM electrolyzers

The reduc­tion of irid­i­um load is pos­si­ble  because of our fun­da­men­tal rethink­ing of elec­trode design. To under­stand our approach, let’s look at the basic struc­ture of a PEM electrolyzer.

It has two elec­trodes sep­a­rat­ed by a thin pro­ton exchange mem­brane (PEM). At one elec­trode, called the anode, the sur­face of the tita­ni­um porous trans­port lay­er (PTL) pressed against the mem­brane must be coat­ed with irid­i­um. This extreme­ly rare and expen­sive met­al acts as a cat­a­lyst to make the reac­tion hap­pen. This is where Smoltek’s break­through inno­va­tion comes in.

Our approach revolves around the inno­v­a­tive use of car­bon nanofibers (CNF): We grow these CNFs direct­ly on the tita­ni­um sur­face that faces the mem­brane, cre­at­ing a struc­ture that mul­ti­plies the sur­face area by 10–30 times. This great­ly enlarged sur­face area means we can spread out and uti­lize the irid­i­um cat­a­lyst much more effi­cient­ly – achiev­ing the same per­for­mance with much less of the pre­cious metal.

We call the com­plete assem­bly – a tita­ni­um PTL with irid­i­um coat­ed CNFs on the mem­brane-fac­ing sur­face – a Porous Trans­port Elec­trode (PTE). This inte­grat­ed approach rep­re­sents a fun­da­men­tal shift from tra­di­tion­al elec­trode design, com­bin­ing struc­tur­al sup­port, increased sur­face area, and cat­a­lyst func­tion­al­i­ty in a sin­gle com­po­nent. The tech­nol­o­gy is strong­ly pro­tect­ed by patents cov­er­ing key aspects of the design and man­u­fac­tur­ing process..

Smoltek’s innovative solution

The effec­tive­ness of this approach has been proven in exten­sive test­ing. By apply­ing irid­i­um to our CNF-enhanced PTL using a pro­pri­etary process, we’ve achieved remark­able results in reduc­ing irid­i­um loading.

Dr. Büchi eval­u­at­ed our elec­trodes with 0.2 mg/​cm² of irid­i­um, which already rep­re­sents a sig­nif­i­cant reduc­tion from the up to 2 mg/​cm² used in tra­di­tion­al electrodes.

Build­ing on these promis­ing results, our devel­op­ment work con­tin­ues toward our tar­get of  0.1 mg/​cm², which would mark a break­through in irid­i­um uti­liza­tion efficiency.

Optimizing for durability

The car­bon nanofibers in Smoltek’s design require pro­tec­tion against the harsh, high­ly oxi­diz­ing envi­ron­ment at the anode. To pre­vent degra­da­tion, we apply a pro­tec­tive lay­er of plat­inum. Dr. Büchi con­firms that this pro­tec­tive lay­er is rel­e­vant for our approach.

Ensur­ing long-term dura­bil­i­ty remains a top pri­or­i­ty. We’re com­mit­ted to exten­sive test­ing under real-world oper­at­ing con­di­tions to ver­i­fy that our efforts nev­er com­pro­mise the reli­a­bil­i­ty and per­for­mance of our electrodes.

Technical advantages

Dr. Büchi’s analy­sis high­lights sev­er­al key strengths of our approach:

The exam­ined irid­i­um load­ing (0.2 mg/​cm²) demon­strates sig­nif­i­cant eco­nom­ic poten­tial, par­tic­u­lar­ly con­sid­er­ing iridium’s high cost and lim­it­ed availability.

The CNF-enhanced sur­face area, which is 10–30 times larg­er than the orig­i­nal PTL mem­brane-fac­ing sur­face, enables more effi­cient cat­a­lyst uti­liza­tion – a key fac­tor in achiev­ing high per­for­mance with reduced mate­r­i­al use.

Ini­tial test­ing con­firms remark­able ini­tial results, achiev­ing 2.5 A/​cm² at 2V at 80 °C – a per­for­mance that, in his words, ”match­es the state of the art.”

This shows that our unique approach to elec­trode design can deliv­er indus­try-com­pet­i­tive per­for­mance while using sig­nif­i­cant­ly less iridium.

Dr. Büchi’s assessment

In his over­all assess­ment Dr Büchi con­cludes: “Smoltek’s elec­trodes are a very inter­est­ing devel­op­ment for the pro­duc­tion of low irid­i­um load­ing elec­trodes for PEM elec­trolyz­ers.” Accord­ing to Dr. Büchi, the tech­nol­o­gy makes it pos­si­ble to cre­ate anodes with a great­ly enlarged sur­face area while using min­i­mal amounts of irid­i­um cat­a­lyst, all inte­grat­ed direct­ly onto the porous trans­port layer.

His eval­u­a­tion includ­ed both exam­in­ing the elec­trode by itself (“ex-situ char­ac­ter­i­za­tion”) and test­ing it under real oper­at­ing conditions.

He notes that “the ex-situ char­ac­ter­i­za­tion of the elec­trodes shows that the aspired goals with high sur­face and low homo­ge­neous spe­cif­ic irid­i­um load­ing can be realized.” 

While these ini­tial eval­u­a­tions are promis­ing, the most com­pelling results come from real-world test­ing. Dr. Büchi exam­ined the elec­trode’s per­for­mance when inte­grat­ed into a com­plete elec­trolyz­er cell, where it worked togeth­er with a mem­brane and cath­ode to pro­duce hydro­gen under actu­al oper­at­ing conditions.

Performance insights

Ear­li­er this year, Smoltek achieved a sig­nif­i­cant mile­stone by suc­cess­ful­ly oper­at­ing a PEM elec­trolyz­er cell for 1,000 hours using only 0.2 mg/​cm² of irid­i­um cat­a­lyst. Dr. Büchi’s thor­ough analy­sis of this dura­bil­i­ty test has now pro­vid­ed valu­able insights into both the tech­nol­o­gy’s capa­bil­i­ties and its path forward.

In his assess­ment, he notes: “The char­ac­ter­i­za­tion in PEM elec­trol­y­sis cells shows that the Smoltek elec­trodes give a very good per­for­mance at begin of life. Though, at the time, a deac­ti­va­tion occurs in the first 10 hours of oper­a­tion.  There are hypothe­ses on the mech­a­nism, but none is proven.”

Let’s break this down: The ini­tial per­for­mance was excel­lent – exact­ly what we were look­ing for. How­ev­er, dur­ing the first 10 hours of oper­a­tion, we observed a decrease in per­for­mance. While the elec­trode con­tin­ued to pro­duce the desired hydro­gen out­put through­out the remain­ing 990 hours, it required slight­ly more elec­tri­cal pow­er than optimal.

The cause of this per­for­mance drop had puz­zled our team until Dr. Büchi’s eval­u­a­tion. His insights pro­vid­ed a like­ly expla­na­tion for the reduced mem­brane con­tact area and, more impor­tant­ly, offered clear path­ways for improve­ment. Based on his rec­om­men­da­tions, we’re imple­ment­ing sev­er­al enhance­ments for our next dura­bil­i­ty test:

• Strength­en­ing the bond between fibers and membrane
• Mod­i­fy­ing the elec­trode configuration
• Upgrad­ing to more sophis­ti­cat­ed test equipment

With these improve­ments in place, we’re con­fi­dent in our path for­ward. Our goal remains clear: demon­strat­ing that our PTE tech­nol­o­gy can match indus­try-stan­dard per­for­mance while using sig­nif­i­cant­ly less iridium.

What does this mean for Smoltek’s future?

Dr. Büchi’s report rein­forces our con­fi­dence in the fun­da­men­tal approach of our PTE tech­nol­o­gy. His inde­pen­dent assess­ment con­firms that our inno­v­a­tive method for reduc­ing irid­i­um load­ing while main­tain­ing high per­for­mance address­es a crit­i­cal indus­try chal­lenge. The report also pro­vides valu­able guid­ance for our con­tin­ued devel­op­ment work.

The path to com­mer­cial­iza­tion in deep tech often requires care­ful atten­tion to detail and sys­tem­at­ic eval­u­a­tion. Each mile­stone we achieve – includ­ing this thor­ough exter­nal review – brings us clos­er to our goal of enabling more effi­cient and sus­tain­able hydro­gen pro­duc­tion. We’re par­tic­u­lar­ly encour­aged by Dr. Büchi’s con­fir­ma­tion that our approach to reduc­ing irid­i­um usage shows promise, as this address­es one of the most sig­nif­i­cant bar­ri­ers to scal­ing up green hydro­gen production.

Your thoughts matter

As share­hold­ers and stake­hold­ers in Smoltek’s jour­ney, your per­spec­tive is invaluable:

• How do you see this review impact­ing Smoltek’s posi­tion in the green hydro­gen market?
• What aspects of Dr. Büchi’s report do you find most encouraging?
• How can we bet­ter com­mu­ni­cate our progress and mile­stones as we work towards commercialization?

Join the dis­cus­sion in the com­ments sec­tion of our LinkedIn post about this arti­cle. Your insights help shape our com­mu­ni­ca­tion strat­e­gy and rein­force the val­ue of patience in devel­op­ing trans­for­ma­tive tech­nolo­gies. Togeth­er, we’re build­ing a foun­da­tion for a more sus­tain­able future.