Scientists in South Korea have created a new, ultra-cheap component for making green hydrogen from water and electricity.
The Korea Institute of Energy Research (KIER) developed a platinum-free, nickel-cobalt electrode for efficient alkaline water electrolysis. This non-precious Ni/Co heterostructure electrode enhances performance and lowers costs in alkaline water electrolysis.
This advance has the potential to remove the primary economic barrier to scaling green energy globally.
“This research proves that non-noble-metal electrodes can achieve world-class performance and durability in alkaline water electrolysis,” said Dr. Kyung-Soo Kang, the lead researcher of the study at KIER.
Cost reduction for green hydrogen
Water electrolysis is wonderfully simple on paper. Send an electric current through water, split the molecules, and capture pure hydrogen gas with zero carbon emissions.
In practice, particularly within large-scale alkaline systems, the reaction is slow. Under alkaline conditions, splitting water molecules takes over 100 times longer than in acidic environments. To speed things up, industrial electrolyzers use precious metals.
Platinum trades at roughly $58 per gram, while ruthenium commands around $54 per gram. Multiply those numbers by the scale of industrial plants, and mass production becomes economically unviable.
The KIER team decided to give up platinum altogether. And built an electrode using nickel and cobalt, priced at a modest $0.02 and $0.05 per gram, respectively.
How do cheap metals beat platinum? The credit goes to the smart architecture.
The team created a dual-component heterostructure that pairs nickel oxide and a nickel-cobalt alloy on a single electrode surface.
Each component handles a distinct stage of the reaction.
Nickel oxide acts as a chemical catalyst, rapidly pulling water molecules apart during the sluggish initial dissociation step. On the other hand, the Ni-Co alloy sweeps in to combine the freed hydrogen ions into usable fuel gas.
Survives stress cycle
The performance results show the potential of this tech. The electrode achieved equal hydrogen production rates at an overpotential of just 22.7 mV, which is roughly 40 percent of the 56.5 mV needed by commercial platinum systems.
“The developed electrode delivers equivalent hydrogen production rates at roughly 40% of the overpotential required by conventional platinum electrodes – demonstrating top-tier performance among non-noble-metal alkaline electrodes reported over the past three years,” the researchers noted.
Many laboratory innovations fail when tested on real-world power grids, where fluctuating solar and wind energy subjects equipment to harsh operating cycles. KIER designed its new electrode specifically to withstand these unpredictable conditions.
In an 8.7-centimeter unit cell test, the electrode reduced cell voltage by 11 percent compared with standard nickel cells. And even survived 600 consecutive start-stop stress cycles without losing performance. In the future, it could run alongside unpredictable solar and wind farms.
The team is already moving past benchtop proofs. Co-lead Dr. Hyun-Jun Lee revealed that the team has fabricated large-scale 40-centimeter-diameter electrodes and is refining manufacturing processes for commercial production. The ultimate goal is to expand electrode surface area to 5,000 square centimeters for direct integration into megawatt-scale industrial plants.
If scaled successfully, this could finally solve hydrogen’s precious-metal tax problem may finally be solved.
The study findings were published in the journal Advanced Science.