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.