Scientists edge closer to stable, cheap green hydrogen production

Scientists from Victoria’s Monash University claim to have made a breakthrough that will bring the inexpensive industrial production of green hydrogen from Australia’s abundant renewable energy generation resources much closer to reality.

The research, which has been described as “critically important” to Australia’s shift to renewables, identifies a variation on water splitting technology, or water electrolysis, that would give it “unparalleled stability,” without blowing out costs.

As we have reported on RenewEconomy, renewable or “green hydrogen” is increasingly being seen as a vital ingredient to Australia’s shift to low-carbon energy generation – not to mention low-carbon transport. But the technology, so far, remains economically and logistically out of reach.

Electrolytic water splitting is widely regarded as the most feasible method for the production of green hydrogen fuel as a versatile means of storage and long-range transportation for the intermittent renewable energy.

More specifically, explains Monash School of Chemistry’s Dr Alexandr Simonov, water splitting using acidic electrolytes is most likely to be the future of the green hydrogen production.

The problem, explains Dr Simonov – who is the lead author of a paper published this week in Nature Catalysis – is that the conditions at the anodes of such devices are extremely harsh, making even highly stable noble metals corrode.

“Renewable energy requires an energy carrier which will allow energy to be transported around Australia and exported in the most efficient manner,” said Dr Simonov, who is also a member of the Australian Centre for Electromaterials Science.

“In a practical context this requires robust electromaterials – catalysts, which can accelerate two half-reactions of the water splitting process – the hydrogen evolution and the oxygen evolution reactions.

So far, Simonov told RE in an interview, the state of the art material used to split water into oxygen and hydrogen has been iridium oxide. But this is one of the rarest elements to source, he says, and still isn’t entirely stable.

“Our research team has introduced an intrinsically stable, ‘self-healing’ catalytic system based on earth abundant elements to promote the water electrolysis process in a strongly acidic environment and elevated temperatures.

“The catalyst demonstrates the state-of-the-art activity, and most importantly, exhibits unparalleled stability under a wide range of aggressive, technologically relevant conditions of water splitting,” he said.

“The outstanding stability in the operation and the low cost of the developed catalytic system identifies it as a potentially suitable option for use in the industrial production of green hydrogen fuel by water electrolysis.”

Study co-author and ARC Laureate Fellow at the Monash School of Chemistry, Professor Doug MacFarlane said the investigation of water oxidation electrocatalysts is a core theme within the Australian Centre for Electromaterials Science, where he leads the energy program.

“It is critically important to the rapidly developing national renewable energy sector,” Professor MacFarlane said.

“This work represents a breakthrough that will bring inexpensive generation of green hydrogen from renewables much closer to reality,” he said. “It is an important development that will further establish Australia’s role as a global powerhouse in the generation and export of renewables.”

So where to from here? According to Dr Simonov, the next big hurdle is to integrate the technology into larger-scale applications.

“Given the very high performance we’ve achieved (in the lab),  it is promising,” he told RE. “The material is exceptionally robust in contrast to everything that has been demonstrated before.

“It has limitations, but they can be solved, and we are working on this.”