Engineering: A new method to make hydrogen fuel from air

A new method to extract water from the air to produce hydrogen is demonstrated in a paper published this week in Nature Communications. These findings may enable future solar-to-fuel conversion devices to operate anywhere on Earth.

Green hydrogen, produced by electrolyzers using electricity and water, represents a potential alternative to CO2-emitting fossil fuels. Electrolyzers can be powered by renewable energy sources, however, current devices often require complex material components, rare metals, and access to pure water, which can lead to competition with limited supplies of drinking water. These factors drive up costs and limit widespread implementation.

Gang Kevin Li and colleagues developed a prototype electrolyzer that harvests humid air instead of liquid water. The device absorbs moisture out of the air and splits the collected water into hydrogen and oxygen. The authors powered the device using renewable energy (solar or wind power) and were able to operate it for 12 consecutive days. They also demonstrate that the device can operate efficiently in a dry environment of around 4% humidity, without the need for liquid water.

The authors suggest that the device is scalable and could be used to provide hydrogen fuel to remote, arid and semi-arid regions with minimal environmental impact.