A revolutionary catalyst, thinner than a strand of DNA, is poised to unlock the hydrogen potential of our oceans.
Most hydrogen today is produced from natural gas, a process that emits large amounts of carbon dioxide. Green hydrogen, made by splitting water using renewable electricity, is the ultimate goal. Yet, this process faces a critical hurdle: it relies heavily on freshwater, a precious and increasingly scarce resource for nearly a third of the world's population 2 .
The solution lies in our oceans. Seawater is over 10,000 times more abundant than freshwater. Using it for hydrogen production would not only preserve drinking water but also open up immense opportunities for coastal and offshore renewable energy systems 2 3 . The challenge has always been that seawater is incredibly corrosive. Its chloride ions rapidly destroy conventional catalysts, making direct seawater electrolysis inefficient and unstable 1 2 .
At the forefront of solving this challenge is a team of researchers, including Professor Yurui Xue from Jilin University, who have engineered a catalyst that is as thin as a catalyst can possibly be—a single layer of atoms 9 .
Their work, published in the Journal of the American Chemical Society, details the creation of a "self-organized gradually single-atom-layer of metal osmium" 9 . This mouthful describes an extraordinary material where active osmium metal is spread out over a support structure in a film just one atom thick.
Visualization of a single-atom-layer catalyst structure
In a single-atom layer, every single metal atom is exposed and available to drive the hydrogen evolution reaction (HER), the key process that produces hydrogen gas. This eliminates waste and maximizes the catalyst's output 9 .
The study reports that this osmium catalyst achieves "unprecedented hydrogen production from seawater" 9 . Its exceptional activity means it can produce large amounts of hydrogen at a very low energy cost.
The self-organizing structure and strong bond with its support material make the catalyst highly resistant to the corrosive chloride ions in seawater, a critical advantage for long-term durability 9 .
So, how did scientists create and test this one-atom-thick marvel? The process is a feat of precision engineering.
The process begins with a suitable support material, which acts as a scaffold. This support is often designed with specific surface properties to anchor metal atoms effectively.
Osmium precursors are introduced in a controlled manner. Through a self-organized growth process driven by carefully tuned chemical conditions, the osmium atoms automatically arrange themselves into a continuous, two-dimensional layer across the support's surface, rather than clumping into larger nanoparticles.
The final structure is treated to ensure a strong chemical bond forms between the osmium atoms and the support, resulting in a stable, single-atom-layer catalyst ready for testing.
When placed in an alkaline seawater electrolyzer, the osmium single-atom layer catalyst delivered exceptional results, significantly outperforming conventional catalysts like commercial platinum/carbon (Pt/C) 9 .
| Catalyst | Overpotential at High Current Density | Stability | Key Advantage |
|---|---|---|---|
| Osmium Single-Atom Layer | Unprecedentedly low | High (maintains performance over long periods) | Maximum atom efficiency, exceptional chloride resistance |
| Pt-Wâ‚‚N Heterostructure 6 | 163.8 mV (at 700 mA cmâ»Â²) | 95.8% activity retention over 80 hours | Synergistic electronic interactions, excellent chloride tolerance |
| Commercial Pt/C | Significantly higher | Lower (vulnerable to chloride corrosion) | Baseline for comparison |
The incredibly low overpotential—the extra energy needed to kickstart the reaction—is a direct result of the single-atom structure. With all atoms participating, the catalyst operates with minimal waste. Furthermore, its stability stems from its strong, integrated structure that resists peeling, dissolving, or being poisoned by chloride ions, a common failure mode for other catalysts 2 9 .
Creating and testing advanced catalysts for seawater electrolysis requires a suite of specialized materials and reagents.
| Reagent/Material | Function in Research |
|---|---|
| Osmium Precursors | The source of osmium atoms for constructing single-atom layers or nanoparticles 9 . |
| Graphdiyne & Other Carbon Supports | A stable, conductive scaffolding material used to anchor and stabilize single metal atoms 9 . |
| Nickel Foam (NF) | A common, porous 3D electrode substrate that provides a large surface area for loading catalyst materials 3 5 . |
| Natural Seawater / Simulated Seawater | The target electrolyte for testing; simulated seawater allows for controlled lab conditions, while real seawater validates performance 2 5 . |
| Alkaline Additives (e.g., KOH) | Added to the electrolyte to create an alkaline environment that suppresses corrosive chlorine chemistry and favors the desired oxygen evolution reaction 2 3 . |
The pursuit of hydrogen from seawater is a vibrant field with multiple parallel breakthroughs. The osmium single-atom layer is a pinnacle achievement, but other innovative approaches are also showing great promise.
Scientists in Korea have developed a catalyst using a two-dimensional material called MXene, combined with nickel ferrite. This composite demonstrates five times higher current density and double the durability of conventional methods by effectively repelling corrosive chloride ions 1 .
A team from MIT has pioneered a completely different path. They use recycled aluminum from soda cans, treated with a gallium-indium alloy, to react with seawater. This process releases hydrogen on-demand and emits as little as one-eighth the COâ‚‚ of conventional fossil-fuel methods 7 .
Many researchers are designing anodes with special protective layers. These can be corrosion-resistant coatings like manganese oxide or layers engineered to have a negative charge that electrostatically repels chloride ions, preventing them from attacking the catalyst 2 3 .
"The development of a self-organized, single-atom-layer osmium catalyst is more than a laboratory curiosity; it is a fundamental step toward a new energy paradigm."
By pushing material design to the atomic limit, scientists have created a system of unparalleled efficiency for turning abundant seawater into clean hydrogen.
Powered by the limitless, rolling waters of the ocean
This breakthrough, alongside other advances in catalyst design and alternative methods, illuminates a clear path forward. It promises a future where our energy systems are powered not by scarred landscapes and polluted air, but by the limitless, rolling waters of the ocean—ushering in a truly sustainable and clean energy future for all.