Scientists turn to nature for a cheaper way to make hydrogen

Schematic diagram of electrode preparation. Credit: Carbon Energy (2023).

Did you know hydrogen, a super useful raw material in agriculture and industry, is mostly made from coal or natural gas, which is harmful to the environment?

It’s true!

But now, a team of scientists from Tel Aviv University have figured out how to make ‘green’ hydrogen using green electricity and a biocatalyst, all without creating any air pollution.

This is a big deal because the majority of hydrogen made today, which is about 95%, is ‘black’ or ‘gray,’ meaning it’s made from coal or natural gas and releases up to 12 tons of carbon dioxide for every ton of hydrogen produced.

So, how does this new process work?

Well, Itzhak Grinberg, a doctoral student and part of the team, explains that hydrogen is rare in our atmosphere, but it is made by tiny organisms through photosynthesis, which is a process that uses sunlight to produce energy.

In the lab, the scientists used an electrode (a device that conducts electricity) to provide energy to these enzymes, mimicking the role of the sun. It’s kind of like giving the enzymes a little electrical boost!

However, the enzyme doesn’t like the electric charge and tries to escape, so the scientists had to figure out a way to keep it in place. They did this by using a hydrogel (a gel made mostly of water) to attach the enzyme to the electrode.

This creative solution led to them successfully producing green hydrogen with a super high efficiency—over 90% of the electricity put into the system was used to make hydrogen.

Professor Iftach Yacoby, another member of the team, added that using the gel to make hydrogen was a new and innovative idea.

The gel helps hold the enzyme for a long time, even under the electric charge, allowing the team to make hydrogen more effectively and under conditions that the enzyme likes, such as in salt water. This is a big advantage, as traditional methods to produce green hydrogen—called electrolysis—require expensive metals like platinum and distilled water.

Professor Lihi Adler-Abramovich added that another cool thing about the gel is that it assembles itself, forming nanometric (super tiny) fibers that help to stick the enzyme to the electrode.

The team also tested the gel with two other enzymes and found it could attach different enzymes to the electrode, which is really promising for future research.

The process we use today to make ‘green’ hydrogen is expensive—it can be up to 15 times more expensive than making ‘gray’ hydrogen, according to Dr. Oren Ben-Zvi.

But with this new method, the team hopes to bring down the costs of making green hydrogen and move towards using it more widely in industry, agriculture, and as a clean energy source. Who knew that nature and a little human ingenuity could create such an exciting solution?

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