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Saturday, September 13, 2014

Quicker, more sustainable way to produce hydrogen fuel

A new method will allow researchers to make larger-than-ever quantities of hydrogen from water, and can be powered by renewable energy sources.
Image: Evan Leeson/Flickr
Scientists in Scotland have just taken a huge step towards producing clean hydrogen fuel in a sustainable way.
Unlike fossil fuels, hydrogen gas can be burned to generate electricity without producing toxic emissions. It’s produced easily from water through a process known as electrolysis, which uses electricity to break the bonds between hydrogen and oxygen, to release them as gas.
But, and this is a big but, the problem is where that electricity comes from - current methods are driven by the burning of fossil fuels, which sort of defeats the whole point of making hydrogen fuel in the first place.
This new method, however, developed by chemists from the University of Glasgow in Scotland, is 30 times faster than the current technique, and also requires a far lower energy load, so that it can be powered by renewable energy sources such as solar or wind. The process is reported in this week’s edition of Science.
The most advanced method of hydrogen production at the moment is known as proton exchange membrane electrolysers (PEMEs). As a University of Glasgow press release explains: “PEMEs require precious metal catalysts to be held in high-pressure containers and subjected to high densities of electric current, which can be difficult to reliably achieve from fluctuating renewable sources.”
This new method, on the other hand, allows larger-than-ever quantities of hydrogen gas to be produced at atmospheric pressure and using lower power loads, such as those generated by renewable power sources.
Even more impressive, it also stores the hydrogen in a carbon-free liquid, which solves some of the safety issues which have so far limited the use of hydrogen fuel.
It does this by using a “liquid sponge” to lock up the protons and the electrons that have the potential to create hydrogen. The “sponge” is a metal oxide that starts off yellow and then turns blue as it's loaded up with this potential to create hydrogen.
"What you do is just turn on the electricity and you split water and you produce this liquid,” Lee Cronin, the leader of the team, told Ken Macdonald from BBC News Scotland. 
"When you want to produce the hydrogen, you don't have to add any more electricity. You just pour this over a catalyst and out comes the hydrogen. And it comes out 30 times faster than the equivalent commercial device."
The method can also help engineers use renewable energy more efficiently. Electricity generated from solar and wind farms is currently difficult to capture, but this breakthrough will allow that electricity to be used immediately to generate hydrogen gas from water, which is much easier to store and transport.
“The potential for reliable hydrogen production from renewable sources is huge. The sun, for example, provides more energy in a single hour of sunlight than the entire world’s population uses in a year. If we can tap and store even a fraction of that in the coming years and decrease our reliance on fossil fuels it will be a tremendously important step to slowing climate change,”said Cronin in the press release.