Move Over Iridium: Northwestern Breakthrough Solves Decades-Old Clean Hydrogen Fuel Problem in a Single Afternoon

The decades-long search for an alternative to iridium, one of the rarest and most expensive metals on Earth, may finally be over, with a new discovery that could accelerate the push for affordable clean hydrogen technologies.

Remarkably, researchers at Northwestern University behind the discovery say they found a viable substitute in just a single afternoon.

By leveraging a powerful new nanomaterial data factory that researchers call a “megalibrary,” the team was able to screen millions of nanoparticles on a single chip at record speeds. Through a collaboration with the Toyota Research Institute (TRI), the team’s powerful new tool helped them uncover a new catalyst made from abundant metals that performs in ways on par with, or even better than, commercial iridium-based materials.

The discovery could help facilitate less expensive green hydrogen production and highlights the promise of the megascale library approach in significantly advancing materials discoveries across various industries.

In the past, identifying new materials has often been a painstaking process of trial and error.

To combat this, nanotechnology pioneer Chad Mirkin created megalibraries—a novel platform where each individual chip contains up to millions of nanoparticles printed with arrays of pyramid-shaped structures that deposit precise mixes of metallic salts.

Mirkin, the senior author of a new study published in the Journal of the American Chemical Society, which describes the team’s findings, said that each pyramid-shaped tip can be thought of as a tiny lab unto itself. When heated, the mixtures they deposit form nanoparticles with tightly controlled compositions and sizes.

“Instead of having one tiny person make one structure at a time, you have millions,” Mirkin explained in a statement. “So, you basically have a full army of researchers deployed on a chip.”

Armed with this innovative technology, the team decided to apply it toward a major hurdle in the production of green hydrogen energy: the oxygen evolution reactor (OER), which involves a step in water splitting that currently relies on iridium as a catalyst.

One of the major issues with the use of iridium is its cost. Currently, this rare Earth metal is valued at close to $5,000 per ounce and is mined only as a byproduct of another rare Earth metal: platinum. This makes it both too rare and too costly to support global clean energy demands.

“There’s not enough iridium in the world to meet all of our projected needs,” said Ted Sargent, a Northwestern researcher and co-author of the recent paper.

However, with help from Mirkin’s megalibrary, the Northwestern team was able to screen combinations of four metals—ruthenium, cobalt, manganese, and chromium—with remarkable speed. The chip used as the sample for this screening contained 156 million nanoparticles, and a robotic scanner evaluated their performance in terms of OER.

Following the team’s analysis, a clear winner stood out among the compositions they examined: a multi-metal oxide with the formal designation of Ru52Co33Mn9Cr6. This specific blend not only appeared to be an almost perfect match for iridium’s activity, but remarkably, it appeared to exceed it in at least a few tests.

Additionally, the novel multi-metal oxide showed promising indications of offering long-term stability that also exceeded that of iridium.

“Our catalyst actually has a little higher activity than iridium and excellent stability,” Mirkin said. “That’s rare because oftentimes ruthenium is less stable. But the other elements in the composition stabilize it.”

Furthermore, durability tests demonstrated that the new catalyst could operate for over 1,000 hours under extremely harsh, acidic conditions without experiencing significant efficiency loss. Best of all, it’s production cost clocks in at close to one-sixteenth that of iridium, making it a far more commercially viable alternative.

Although additional research is still required, the team says the results are extremely promising.

“There’s lots of work to do to make this commercially viable, but it’s very exciting that we can identify promising catalysts so quickly — not only at the lab scale but for devices,” said TRI’s Joseph Montoya, a co-author of the study.

Even beyond the team’s most recent achievement, their study demonstrates how megalibraries can be leveraged to assemble massive datasets that can be paired with artificial intelligence and machine learning to provide new avenues for discovery in materials science.

Mirkin believes what his team has achieved is really is just the beginning of more exciting discoveries to come.

“The world does not use the best materials for its needs,” he said. “People found the best materials at a certain point in time, given the tools available to them.”

“We want to turn that upside down,” Mirkin added. “It’s time to truly find the best materials for every need — without compromise.”

The team’s discovery was detailed in the recent paper, “Accelerating the Pace of Oxygen Evolution Reaction Catalyst Discovery through Megalibraries,” published in the Journal of the American Chemical Society.

Micah Hanks is the Editor-in-Chief and Co-Founder of The Debrief. A longtime reporter on science, defense, and technology with a focus on space and astronomy, he can be reached at micah@thedebrief.org. Follow him on X @MicahHanks, and at micahhanks.com.

Uh hydrogen is an industrial chemical used by the millions of tonnes per year. Texas has a couple hundred miles worth of hydrogen pipelines in the petro industrial complex that runs from Texas City east into Louisiana. Hydrogen is critical to cracking petroleum products and taking the sulfur out of gasoline and diesel. Currently that hydrogen is made cracking methane with high temp and pressure steam.

Point is hydrogen is produced , stored , transported and used every day in massive amounts. It’s fudd lore that it leaks out of everything, aluminum lined carbon fiber vessels are impervious to H2 and aluminium doesn’t get brittle like iron alloys. Hannah solved the hydrogen issues 30 years ago.

Any process that lowers the cost of hydrogen production is a boom for the chemicals and petrochemicals industry. Every large electrical generator as in gas turbine and nuclear powered size are cooled with hydrogen gas as it’s the most efficient coolant gas. Think about that fact. Large spinning metal mass bathed in hydrogen if humans had not mastered its control and isolation we wouldn’t use it right next to nuclear reactors with multiple tonnes of hot spinning mass totally dependent on its containment ,flow and cooling.

The barrier to electrolysis cost is the catalysts replacing iridium with a nano metal oxide would break the $200 per kg threshold. At those costs your cost per kg is all dependent on the cost of the electrons driving the electrolysis. You can then run the machines intermittently not 24/7 this allows the whole equation to shift from demand based to supply based electricity. All of a sudden when you have like yesterday at 1145 am in Texas $4.65 per megawatt hour electricity for sale that’s 4/10s of a cent per kWh it takes 52 kWh to make a Kg of H2 at that cost its 24 cents per kg of H2 even with zero costs methane you couldn’t get to that price with steam methane reforming.

As a point there is the same energy in a Kg of H2 as in 1 US gallon of gasoline. To make synthetic fuel via FT using H2 and CO2 you need 3:1 H2 to CO2 the overall process is 33% efficient so you end up consuming 3 kg of H2 to yield one gallon of synthetic fuel.

At $5 per MWh its 78 cents for 3 Kg of H2 with $200 in capex per kg per hour in electrolysis costs over the 30,000 hour lifespan of the unit its fractions of a cent per kg in capex the bulk cost is the electrons.

Better would be to go to methanol which needs 2:1 H2 to CO2 for synthesis then use zeolite Z5 Exxon catalysts to go to gasoline and propane in a 70/30 ratio you save one Kg of H2 per gallon that way or just use the methanol as is its over 100 octane Indy cars and dragster used it for decades before moving to ethanol.

The critical breakthrough is the catalysts which these guys just broke that barrier. Electrons are cheap when the wind blows and the Sun shines sub $5 per MWh from either in real world ERCOT market the largest independent grid in North America.

Even $10 per MWh would only be $1.56 for FT and $1.04 for MTG or methanol direct. Canadian or S.Korean nukes can put out $18 MWh to the plant gate at 90% uptime per year. Again once you have economical catalysts hydrogen based chemicals and synthetics become cheaper than digging it out of the middle east and shipping it half way around a planet. Plus you now have unlimited supplies due to only needed water and not even fresh water plus CO2 from the air. Biomass is nothing but air CO2 turned into a solid that you literally can pick up off the ground all over the planet and from the oceans via seaweed.

The USA has over 1 billion tonnes of waste biomass per year with cheap catalysts and intermittent but cheap electrons or 24/7 nuke electrons 90% of that can be turned into fuels via FT or MTG

https://www.greencarcongress.com/2018/08/20180812-pbtl.html

The great enabler is lowering the catalyst costs.

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