how to make hydrogen straight from seawater

 

For years, hydrogen has been considered the fuel of the future with great potential to combat environmental problems. Currently, however, almost all of the world’s hydrogen is derived from fossil fuels, and its production emits about 830 million tons of carbon dioxide annually. Emissions-free ‘green’ hydrogen, obtained by splitting water, does exist, but it is so expensive that it is hardly commercially viable, justifying only 1% of total hydrogen production worldwide.

 

With this in mind, a team of researchers at RMIT University in Melbourne, Australia, has developed a new and improved method for producing hydrogen from seawater that splits the water directly into hydrogen and oxygen – without the need for desalination and its associated costs, energy consumption, and carbon emissions. ‘Our method to produce hydrogen straight from seawater is simple, scaleable, and far more cost-effective than any green hydrogen approach currently in the market,’ shares Lead researcher Dr. Nasir Mahmood. ‘With further development, we hope this could advance the establishment of a thriving green hydrogen industry in Australia.’

researchers develop cheap, energy-efficient way to make hydrogen directly from seawater
Mr Suraj Loomba, Dr Nasir Mahmood and Dr Muhammad Waqas Khan are part of the research team | all images courtesy of RMIT University

 

 

Splitting the difference: a catalyst for seawater

 

In order to produce green hydrogen, the researchers at RMIT (find more here) used an electrolyzer to send an electric current through water and split it into its component elements of hydrogen and oxygen. At the moment, these electrolyzers use expensive catalysts and consume a lot of energy and water — it takes about nine liters to produce one kilogram of hydrogen. In addition, they produce a toxic product: chlorine.

 

‘The biggest hurdle with using seawater is the chlorine, which can be produced as a by-product. If we were to meet the world’s hydrogen needs without solving this issue first, we’d produce 240 million tons per year of chlorine each year – which is three to four times what the world needs in chlorine. There’s no point replacing hydrogen made by fossil fuels with hydrogen production that could be damaging our environment in a different way,’ Mahmood says. ‘Our process not only omits carbon dioxide, but also has no chlorine production.’

researchers develop cheap, energy-efficient way to make hydrogen directly from seawater
the new method from rmit university researchers splits seawater directly into hydrogen and oxygen

 

 

developing a special new catalyst

 

The new approach was developed by a team in the Materials for Clean Energy and Environment (MC2E) research group at RMIT, and uses a special type of catalyst created to work specifically with seawater. The study put emphasis on producing efficient, stable catalysts that can be produced cost-effectively. ‘These new catalysts take very little energy to run and could be used at room temperature,’ Mahmood explains. ‘While other experimental catalysts have been developed for seawater splitting, they are complex and hard to scale.’

 

Mahmood also notes that this technology has the potential to decrease the cost of electrolyzers — enough to meet the Australian Government’s goal for green hydrogen production of $2/kilogram, to make it competitive with fossil fuel-sourced hydrogen.

researchers develop cheap, energy-efficient way to make hydrogen directly from seawater researchers develop cheap, energy-efficient way to make hydrogen directly from seawater