Hydrogen is often described as a clean fuel of the future.
It can power trucks, help make fertilizer, and store large amounts of energy from renewable sources.
The big problem is that most hydrogen today is still produced using fossil fuels such as natural gas and coal, which release huge amounts of carbon dioxide.
Scientists have long known that hydrogen can also be made by splitting water using electricity, a process called electrolysis, which creates hydrogen and harmless oxygen gas.
The challenge is that this cleaner method is still too expensive for widespread use.
Now, a team led by Professor Shannon Boettcher at the University of California, Berkeley has developed a new approach that could dramatically reduce the cost and improve the lifespan of the machines that make hydrogen from water.
Their work focuses on a key weak point in today’s electrolyzers: the electrodes, which are the parts where the chemical reactions happen.
Electrolyzers need electricity to split water into hydrogen and oxygen. If that electricity comes from solar or wind power, the process can be almost completely green. However, renewable energy is not available all the time.
The sun doesn’t always shine and the wind doesn’t always blow.
That means electrolyzers may only run part of the time, which makes their high cost harder to justify. To make green hydrogen affordable, these systems must be much cheaper and more durable.
There are two main types of electrolyzers in use today. One uses a very strong alkaline liquid, similar to drain cleaner, which makes it difficult to maintain and scale up.
The other uses an acidic membrane that is safer and more efficient, but it requires expensive metals like iridium and special “forever chemicals” that are harmful to the environment and difficult to break down.
Boettcher’s team is working on a different type of system called an anion-exchange membrane electrolyzer. This design combines the benefits of a solid membrane with a more affordable, alkaline environment.
In theory, it allows the use of cheaper materials and safer operation. In practice, however, these systems have suffered from a critical problem: the polymer materials in the electrodes wear out quickly.
When oxygen is produced at the positive electrode, it pulls electrons away from the polymer, slowly destroying it. This kind of damage is similar to what happens inside a dying battery.
To solve this problem, the researchers added a new protective ingredient: a zirconium oxide polymer. This material mixes with the existing organic polymer and forms a protective “shield” around the electrode.
This shield prevents the electrons from being stripped away and dramatically slows down the damage. According to Boettcher, the new design reduces the rate of degradation by as much as one hundred times.
In their design, a cobalt-based material is placed onto a steel mesh, and then the special polymer mixture is layered on top. This creates a strong, protected anode where oxygen is formed. The other side, the cathode, produces hydrogen. Together, these form a much more stable and efficient system for splitting water.
While the technology is not yet ready for full commercial use, the results are extremely promising.
The team continues to refine the design and test it under different conditions. If successful, this breakthrough could make green hydrogen much more affordable and help it compete with fossil fuels without the need for government subsidies.
As Boettcher explains, hydrogen still faces challenges in production, storage, and transport. But the progress is happening fast. With innovations like this, the day when clean, affordable hydrogen becomes a major part of our energy system may be much closer than we think.
Source: UC Berkeley.
