Scientists at the University of Glasgow have made an exciting clean energy production breakthrough: they’ve discovered a new method for extracting hydrogen from water that is not only safer than current methods, it’s also an incredible 30 times faster. The process, published in the journal Science, also resolves issues associated with storing electricity generated by renewable resources by using that electricity to produce hydrogen, which can then be stored for later use.
In nature, photosynthesis splits water molecules to provide protons and electrons for plant growth. Oxygen is a byproduct of the process and it’s released out into the atmosphere, where it kind of comes in handy. However, chemists are more interested in splitting water to produce hydrogen and create fuel. The trick to the process lies in keeping the highly reactive hydrogen and oxygen produced separate, otherwise things can get a little, ahem, explosive. When the separated hydrogen gas is intentionally burned as a fuel, however, it is considered to have zero emissions, and therein lies its appeal.
The UoG breakthrough means that it becomes practical to use renewable energy sources rather than fossil fuels to power the process of splitting the water molecules. Not only is it a less energy-intensive process, it doesn’t require the use of precious metal catalysts like the current most effective renewables-based method, known as proton exchange membrane electrolysers (PEMEs). Leader of the research team Professor Lee Cronin explains: “The process uses a liquid that allows the hydrogen to be locked up in a liquid-based inorganic fuel. By using a liquid sponge known as a redox mediator that can soak up electrons and acid we’ve been able to create a system where hydrogen can be produced in a separate chamber without any additional energy input after the electrolysis of water takes place. The link between the rate of water oxidation and hydrogen production has been overcome, allowing hydrogen to be released from the water 30 times faster than the leading PEME process on a per-milligram-of-catalyst basis.”
In more lay terms, Professor Cronin elaborated on the concept of the liquid sponge to the BBC. The sponge is actually a metal oxide that changes color from yellow to blue as it soaks up protons and electrons from the hydrogen. Showing off the blue liquid Professor Cronin said, “What you do is just turn on the electricity and you split water and you produce this liquid. 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.” While the breakthrough has only just been announced, Professor Cronin estimates that the now-patented process is about 10 years away from being scaled up to commercial production. The team are now hoping to develop commercial partnerships.