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.