Smoltek can radically reduce the iridium catalyst loading in PEM electrolyzers

With­in the hydro­gen busi­ness area, Smoltek devel­ops a cell mate­r­i­al for PEM elec­trolyz­ers (Smoltek ECM) with a goal to min­i­mize the amount of the rare pre­cious met­al irid­i­um in the elec­trolyz­er cell (the irid­i­um cat­a­lyst load­ing). The elec­trolyz­ers will thus become much cheap­er to man­u­fac­ture. The reduced amount of irid­i­um per elec­trolyz­er will also help enable glob­al scale-up of PEM elec­trolyz­ers, which are essen­tial for the pro­duc­tion of fos­sil-free hydrogen.

The results of these tests have been ver­i­fied, and they show that with a cal­a­lyst load of only 0.5 mg of iridium/​cm2, Smoltek’s pro­to­types pro­duce the same amount of hydro­gen as a con­ven­tion­al cell does with 2.5 mg of iridium/​cm2.

The improve­ment is due to the devel­op­ment of the com­pa­ny’s unique cell mate­r­i­al and the three-dimen­sion­al nanos­truc­ture the cor­ro­sion-coat­ed car­bon fibers pro­vide. The next step is to start tun­ing var­i­ous tech­ni­cal para­me­ters to fur­ther improve the tech­nol­o­gy and reach the goal of 0.1 mg irid­i­um per square centimeter.

“This is an incred­i­bly pleas­ing result for us. Already today, the irid­i­um price is up to SEK 2 mil­lion per kilo­gram and is expect­ed to rise to SEK 8–10 mil­lion per kilo­gram before the end of the decade. This shows that our con­cept is extreme­ly strong.”

Elli­nor Ehrn­berg, Pres­i­dent of Smoltek Hydrogen

The pro­to­types, devel­oped by the group com­pa­ny Smoltek Hydro­gen in col­lab­o­ra­tion with a large indus­tri­al man­u­fac­tur­er of elec­trolyz­ers mate­ri­als (com­po­nents), have been test­ed by a promi­nent Ger­man tech­ni­cal insti­tute. Smoltek’s cell mate­r­i­al have been assem­bled into pro­to­types (demon­stra­tors) of com­plete elec­trolyz­er cells and test­ed these against con­ven­tion­al cells.

The tests indi­cate that the same capac­i­ty is reached with the Smoltek cell mate­r­i­al as with a stan­dard mate­r­i­al, which in this case con­tains five times more irid­i­um than the Smoltek mate­r­i­al. This means that Smoltek Hydro­gen’s sub-goal of get­ting down to 0.2 mg of irid­i­um per square cen­time­ter is with­in reach. The next devel­op­ment step is to start tun­ing var­i­ous tech­ni­cal para­me­ters to get clos­er to the goal of only need­ing 0.1 mg irid­i­um per square centimeter.

In addi­tion, the ini­tial long-term tests have also yield­ed pos­i­tive results where Smoltek’s pro­to­types have passed a 1,000-hour test with­out degrad­ing. It shows that the cor­ro­sion-resis­tant coat­ing pre­vents the car­bon nanofibers from break­ing down in the high­ly cor­ro­sive envi­ron­ment of the anode side where the water main­tains a pH val­ue of 0.

Facts, Smoltek ECM (Elec­trolyz­er Cell Mate­r­i­al):
Smoltek’s pro­pri­etary mate­r­i­al for elec­trolyz­ers is a three-dimen­sion­al nanos­truc­ture-based coat­ing devel­oped to rad­i­cal­ly reduce the irid­i­um cat­a­lyst load­ing and increase pro­ton through­put in an elec­trolyz­er cell.