A material best known for keeping eggs from sticking to frying pans may help solve one of clean energy’s biggest challenges.
Researchers have discovered that a simple Teflon-based coating can boost hydrogen production in water electrolyzers by about 40%, using a method that is cheap, practical, and easy to scale up.
The study was led by Professors Jungki Ryu and Dong Woog Lee from the School of Energy and Chemical Engineering at UNIST in South Korea.
Their work was published in Advanced Science and selected as a cover article, highlighting its significance for future energy technologies.
Water electrolyzers produce hydrogen by using electricity to split water into hydrogen and oxygen. This process is central to “green hydrogen,” which can store renewable energy and power industries without carbon emissions. However, electrolyzers face a surprisingly simple problem: hydrogen bubbles.
As hydrogen forms on the electrode surface, bubbles tend to stick to it. When that happens, they block active areas where the reaction should take place. This reduces efficiency, slows hydrogen production, and forces the system to use more energy to maintain performance.
The UNIST team tackled this issue with a clever solution. They applied a thin coating of polytetrafluoroethylene, or PTFE—better known as Teflon—onto a key component inside the electrolyzer called the porous transport layer, or PTL.
The PTL plays a dual role: it supplies water to the catalyst while also helping remove the hydrogen gas that forms.
Because PTFE is highly water-repellent, hydrogen bubbles do not stick to it. Instead, the bubbles detach quickly and escape, keeping the catalyst surface clear and active. This simple change allows the electrochemical reaction to proceed more smoothly.
To avoid interfering with water flow, the researchers coated only the upper half of the PTL, where hydrogen exits the system, and left the lower half uncoated. This careful design ensured that water could still reach the catalyst efficiently while hydrogen was removed more easily.
The results were striking. Electrolyzers using the partially coated PTL showed a 40% increase in current density, a key measure of hydrogen production rate. The system also experienced less voltage buildup caused by trapped gas, which further improved overall energy efficiency.
One of the most appealing aspects of this approach is how easy it is to apply. The coating is added through a simple spray process followed by heat treatment, without the need for complex manufacturing techniques. The team successfully coated large components up to 225 square centimeters, showing the method is suitable for industrial-scale systems.
Professor Ryu noted that while many engineers focus on making electrolyzer components more water-loving, this study shows that a water-repellent surface can actually improve performance by helping gas escape. Professor Lee added that because Teflon is widely available and existing systems do not need redesigning, this technique could be adopted quickly. Beyond hydrogen production, it may also improve other technologies that involve gas formation, such as fuel cells and metal-air batteries.
Sometimes, the biggest breakthroughs come from the simplest ideas—and in this case, from a non-stick surface hiding in plain sight.
Source: Knowridge Science Report.
