Hydrogen extraction set to become cheaper after discovery of new method

In a potentially significant development for the future of Australia’s budding hydrogen economy, research teams from UNSW Sydney, Griffith University and Swinburne University of Technology have collaborated to publish research that demonstrates a way of capturing hydrogen using low cost metals.

Available in Nature Communications, the research has identified the possibility using cheap metals such as iron and nickel as a catalyst, which would make the chemical reaction needed to split oxygen in water to create hydrogen require much less energy.

Head of Nanoelectrochemistry at UNSW, Chuan Zhao, said that this breakthrough discovered by his team had the potential for real world application, particularly with Australia’s recent investments in hydrogen.

“At the moment in our fossil fuel economy, we have this huge incentive to move to a hydrogen economy so that we can be using it as a clean energy carrier which is abundant on Earth,” said Zhao.

“We’ve been talking about the hydrogen economy for ages, but this time it looks as though it’s really coming.”

Zhao believes that if developed further, the process of splitting water using cheap catalysts could one day result in the arrival of hydrogen refuelling stations where you would pull-up and fill your hydrogen fuel-cell vehicle with hydrogen gas in minutes, much the same way as petrol stations currently operate. This would blow the charge time of battery electric vehicles out of the water, while providing an environmentally sound fuel source.

“We’re hoping our research can be used by stations like these to make their own hydrogen using sustainable sources such as water, solar and these low cost, efficient, catalysts.”

The process of splitting water for hydrogen involves two electrodes covered in a catalyst applying an electric charge to water, which allows the hydrogen to be split from the oxygen.

The catalyst used in this process is usually ruthenium, platinum or iridium, all precious, expensive metals.

Iron and nickel, by contrast, are much cheaper metals but are not good catalysts. However, combining the two metals at a nanoscale is “where the magic happens” according to Zhao.

“The nanoscale interface fundamentally changes the property of these materials. Our results show the nickel-iron catalyst can be as active as the platinum one for hydrogen generation.”

“An additional benefit is that our nickel-iron electrode can catalyse both the hydrogen and oxygen generation, so not only could we slash the production costs by using Earth-abundant elements, but also the costs of manufacturing one catalyst instead of two.”

Moving away from ruthenium, platinum and iridium to iron and nickel would prove to be financially beneficial.

While iron and nickel are priced at just $0.13 and $19.65 per kilogram respectively, ruthenium costs $11.77 per gram, platinum $42.13 per gram, while iridium comes in at $69.58 for one gram.

Original source: Australia’s Science Channel | Splitting hydrogen from water just got a whole lot cheaper and easier

17 Dec 2019