Using unpretreated seawater to produce green hydrogen

A team of researchers from the University of Adelaide have successfully obtained hydrogen from seawater, without desalinating it, and using a cheap catalyst.

The study, published in the journal Nature Energy, was conducted by an international team led by Professor Shizhang Qiao of the University of Adelaide. On the University’s website, he reveals that the researchers succeeded in separating oxygen from hydrogen in seawater with nearly a 100% efficiency. An achievement that seems already miraculous in itself. What’s more, no pre-treatment of the seawater was needed (reverse osmosis desolation, purification, alkalisation).

To carry out the electrolysis, the researchers used cobalt oxide with chromium oxide on its surface. The advantage of this solution is that it is cheaper and does not require precious metals, as do conventional catalysts that use platinum and iridium. The other significant advantage is you don’t need to use highly purified water to get green hydrogen and, as you are aware, seawater is an abundant raw material that covers three quarters of the planet.

Associate Professor Yao Zheng, who co-led the works, thinks that such a solution is ideal for countries long coaster lines. The team will now work on a larger electrolyser so that it can be commercialised.

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Article written by Laurent Meillaud and translated by Logan King