Australian research could unlock way to make cheap renewable hydrogen while absorbing CO2

Researchers have discovered new materials that could hold the key to the low-cost conversion of carbon dioxide into hydrogen fuels, fertilisers and other chemicals, that also avoid the need for fossil fuels.

The research has been published in the academic journal Nature Communications, and was undertaken by a team of researchers at the Toowoomba based University of Southern Queensland (USQ), with PhD student Yangli Pan leading the preparation of the paper.

Lead USQ researcher Dr Lei Ge of the University of Southern Queensland said that the research team had identified alternatives to expensive precious metals that had been previously used in the hydrogen production process.

The researchers see an opportunity for the cheaper and more readily available materials to provide a pathway to lower cost hydrogen production and  fuels, fertilisers and chemical feedstocks needed by industry and society.”

Dr Ge said that there was an exciting opportunity for hydrogen to play a role in replacing some of the traditional fossil fuels used widely in Australia’s energy and manufacturing system.

“Fossil-fuel driven processes currently dominate the chemical and fuel manufacturing industry, relying on large non-renewable sources such as coal or oil,” Dr Ge said.

“A possible sustainable future could integrate renewable energy from more plentiful small gas molecules, for example carbon dioxide.”

While the main focus for renewable hydrogen production has been on the use of renewable electricity to split water into hydrogen and oxygen, there are alternative ways of producing hydrogen through other chemical reactions, including some that draw upon carbon dioxide taken from the atmosphere.

This includes an electrochemical technique that can use renewable electricity to convert inputs like carbon dioxide and water into useful fuels and chemicals like hydrogen and ammonia. It provides an opportunity for the conversion of renewable energy into fuels to be undertaken using a process that is potentially carbon negative.

However, the catalysts presently used to kick-start these reactions have generally been expensive metals, including iridium and ruthenium, as they provided the best performance and conversion efficiencies.

In the new research paper, the Queensland-based scientists uncovered new low cost materials that could be adapted to provide good performance while allowing for significant reductions in price.

“An important part of that process is an electrocatalyst called the anodic oxygen evolution reaction, but a drawback has been the expense and scarcity of the precious metals traditionally used to make it work,” Dr Ge added.

“Instead of precious metals, we’re investigating a ceramic-based oxide which is more stable and more efficient in sparking the necessary chemical reaction.”

“This project is significant because it aims to overcome critical issues in electrochemical technologies that could potentially produce, using renewable energy sources, a wide range of chemicals (fuels, fertilisers, chemical feedstocks) needed by industry and society.”

The research was undertaken in partnership with Curtin University and the University of Queensland, and received funding support from the Australian Research Council. The research was undertaken by USQ’s materials group within the university’s School of Mechanical and Electrical Engineering, led by Professor Hao Wang.

In a related breakthrough, researchers from the Australian National University recently published the findings of new low-cost techniques for the direct conversion of solar energy to hydrogen within specially designed solar cells, that have the potential to significant cut the cost of renewable hydrogen production.

The ANU researchers set an “unprecedented” new world record for the conversion efficiency of solar-to-hydrogen, which integrates the ability to split water into hydrogen and oxygen into the solar panel itself, avoiding the need for additional power infrastructure like inverters and network transmission, as well as avoiding the need for a stand-alone electrolyser.