Smoltek’s PTE technology stands out expert states in interview

Dr. Büchi, who has over 20 years of expe­ri­ence in PEM elec­trol­y­sis at the pres­ti­gious Paul Scher­rer Insti­tut, empha­sizes that Smoltek’s approach rep­re­sents a fun­da­men­tal break­through in elec­trode design. “The unique­ness of the approach is not to use nanopar­ti­cles but to use a nanosur­face,” Büchi explains. “This Smoltek irid­i­um nanosur­face is based on a con­duct­ing sub­strate so in prin­ci­ple all the irid­i­um can be well accessed.”

Unlike con­ven­tion­al meth­ods that rely on irid­i­um nanopar­ti­cles, Smoltek has devel­oped a unique way to mul­ti­ply the cat­alyt­ic sur­face area by grow­ing car­bon nanofibers direct­ly on the porous trans­port lay­er (PTL), enabling effi­cient cat­a­lyst uti­liza­tion with min­i­mal irid­i­um loading.

Achieving same performance with 90% less iridium

Büchi’s assess­ment con­firms that Smoltek’s tech­nol­o­gy deliv­ers lead­ing indus­try stan­dard per­for­mance while using only 0.1–0.2 mg/​cm² of irid­i­um, com­pared to the 1–2 mg/​cm² typ­i­cal­ly required. This rep­re­sents a reduc­tion of up to 95 % in irid­i­um usage – a crit­i­cal advan­tage giv­en that irid­i­um is much more expen­sive than gold and has extreme­ly lim­it­ed avail­abil­i­ty with only 5–7 tons mined annu­al­ly worldwide.

A unique solution in high demand

“The main asset of the Smoltek solu­tion – and this is unique – is the abil­i­ty to pre­pare a low amount of irid­i­um onto the PTL because you are able to pre­pare a high sur­face area on the PTL,” Büchi explains. He con­firms that irid­i­um remains the only known sta­ble cat­a­lyst for PEM elec­trol­y­sis, mak­ing tech­nolo­gies that reduce irid­i­um usage high­ly valu­able for elec­trolyz­er manufacturers.

Technical advantages of Smoltek’s approach

Büchi high­lights how Smoltek’s solu­tion dif­fers fun­da­men­tal­ly from con­ven­tion­al approach­es. While oth­ers strug­gle with par­ti­cle-based meth­ods where cat­a­lyst islands can become elec­tron­i­cal­ly iso­lat­ed, Smoltek’s con­duc­tive base lay­er ensures that ”all of your cat­a­lyst remains on the sur­face, none of it dis­ap­pears in the bulk of the tita­ni­um PTL.” This effi­cient cat­a­lyst uti­liza­tion is key to achiev­ing high per­for­mance with min­i­mal iridium.

Clear path forward for optimization

The assess­ment also iden­ti­fied oppor­tu­ni­ties for fur­ther opti­miza­tion. Ini­tial dura­bil­i­ty tests showed some per­for­mance decline dur­ing the first 10 hours of oper­a­tion, which Büchi attrib­ut­es to pres­sure from evolv­ing oxy­gen poten­tial­ly caus­ing delam­i­na­tion between the elec­trode and membrane.

How­ev­er, he sug­gests there are sev­er­al engi­neer­ing solu­tions to address this. One approach would be to make the cat­a­lyst lay­er more porous, allow­ing gas to escape more eas­i­ly. Anoth­er would be to intro­duce what is called a micro­p­orous lay­er with small­er grains, reduc­ing pres­sure buildup between the grain and mem­brane. Both are rel­a­tive­ly straight­for­ward mod­i­fi­ca­tions com­pared to the fun­da­men­tal tech­nol­o­gy devel­op­ment already achieved.

Potential for even greater iridium reduction

Look­ing ahead, Büchi sees promis­ing oppor­tu­ni­ties for push­ing the bound­aries of irid­i­um reduc­tion even fur­ther. His assess­ment indi­cates that Smoltek’s sur­face-based approach could poten­tial­ly achieve even low­er irid­i­um load­ing while main­tain­ing per­for­mance lev­els. This poten­tial for con­tin­ued opti­miza­tion under­scores the fun­da­men­tal advan­tages of Smoltek’s inno­v­a­tive elec­trode design.

With cur­rent results already show­ing a 90 % reduc­tion in irid­i­um usage, any addi­tion­al improve­ments would fur­ther strength­en Smoltek’s posi­tion at the fore­front of PEM elec­trolyz­er tech­nol­o­gy devel­op­ment. The proven sur­face-based approach cre­ates an ide­al foun­da­tion for ongo­ing refine­ment and enhance­ment, sug­gest­ing that today’s impres­sive results may be just the beginning.

Market ready for implementation

For elec­trolyz­er man­u­fac­tur­ers, reduc­ing irid­i­um usage rep­re­sents a sig­nif­i­cant oppor­tu­ni­ty to low­er costs and address sup­ply con­straints. Büchi con­firms that Smoltek’s tech­nol­o­gy match­es indus­try stan­dards for per­for­mance while dra­mat­i­cal­ly reduc­ing pre­cious met­al require­ments, mak­ing it an attrac­tive solu­tion for com­mer­cial implementation.

Want to learn more about how Smoltek’s unique tech­nol­o­gy can rev­o­lu­tion­ize PEM elec­trol­y­sis? Watch the com­plete inter­view with Felix Büchi, where he pro­vides detailed insights into the technology’s advan­tages and mar­ket potential.