University of Sydney engineers devise water-to-hydrogen tech

Researchers from the University of Sydney have devised a method to efficiently convert water into hydrogen, making strides in its development as a clean energy store for fuel cells.

Historically, the uptake of hydrogen as a fuel has been hindered by high costs and the vast amount of energy required for its production.

Although hydrogen is part of the water compound H₂O, highly reactive, pure hydrogen is scarcely found on earth and is notoriously complex to work with.

The water-splitting process — which rips hydrogen away from oxygen, turning H₂O into H₂ — has not been widely adopted, mainly because of the prohibitive cost of precious metals, like platinum or ruthenium, normally used as catalysts.

Methods to split water are also often unfeasibly energy intensive, and the required catalyst materials can break down too quickly before the necessary change occurs.

A hydrogen fuel cell creates electricity using hydrogen, with water and heat as its only by-products. Hydrogen therefore has the potential to decarbonise industries like aviation and transport.

The team of engineers led by FH Loxton Research Fellow Dr Shenlong Zhao from the School of Chemical and Biomolecular Engineering has created an efficient water-splitting catalyst that requires less energy to produce pure hydrogen than earlier catalysts. The team’s paper is published in Nature Energy.

How the catalyst works

The researchers used nickel, iron and cobalt to create a series of porous, metal-organic framework nanocrystals, which presented a unique atomic structure and many exposed surfaces throughout the material.

The framework successfully catalysed a reaction using less energy than catalysts that use more expensive materials. The catalyst also showed very little loss in activity in a 150-hour stability test.

“We are on the cusp of the hydrogen age: the adoption of large-scale hydrogen technology is finally within striking distance. Targeted investment and research in this area would usher in a new age of truly transformative renewable energy,” lead author Dr Zhao said.

“Because energy from solar and wind sources is intermittent, our research sought to discover an efficient way of storing renewable-sourced power.

“Improvements in energy conversion and storage are absolutely essential for a successful and sustainable energy economy. Because energy from solar and wind sources is intermittent, our research sought to discover an efficient way of storing renewable-sourced power,” Dr Zhao said.

Head of the School of Chemical and Biomolecular Engineering Professor Dianne Wiley added, “Our team has developed an exciting new catalyst based on iron, cobalt and nickel that can be used to create pure hydrogen.”

Dr Zhao’s colleague and recipient of the 2020 Prime Minister’s Prize for Innovation, Professor Thomas Maschmeyer from Sydney Nano and the School of Chemistry, said Australia was in a good position to capitalise on the technology.

“Australia is extremely well placed to advance green hydrogen technology, both as manufacturer and consumer. Hydrogen can be used for energy storage as well as an agent replacing gas, oil and coal,” Professor Maschmeyer said.

“Not only are we the world’s largest iron-ore producer and a leading supplier of nickel and cobalt, but our abundance of sunshine and wind means that hydrogen could transform our domestic energy system as well as create many opportunities in sustainable manufacturing,” he said.

Dr Zhao commented, “Just recently we witnessed a worldwide commitment to a clean energy future. What we now require is significant investment from industry and government to wholly develop hydrogen technologies.”

The NSW Government recently announced a $32 billion renewable energy plan. Dr Zhao believes research like his could be used to develop long-range hydrogen powered aircraft and fuel cells for industrial purposes.

The team now hopes to work with a collaborator to build a larger-scale device.

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