Cheap, efficient electrocatalyst a ‘gamechanger’ for green hydrogen

Hydrogen has the potential to be a zero-carbon fuel source which produces just heat and water when burned or used in fuel cells. This makes it a highly attractive alternative to fossil fuels in heating and transport. A pillar of the UK government’s decarbonisation plan is a huge expansion of hydrogen to 5GW capacity by 2030.

As hydrogen is currently much more expensive to produce than the fuels it could replace, the government is considering providing subsidies to bridge the gap, controversially supporting both green and blue hydrogen (the latter of which can be more polluting than coal). While blue hydrogen is produced from natural gas, green hydrogen is produced by splitting water via electrolysis into hydrogen and oxygen. While green hydrogen is the preferred option given its potential to produce no carbon overall, the process is not yet efficient enough for scaling up.

Typically, scientists have used precious metal catalysts, such as platinum, to accelerate the reaction to produce green hydrogen. Now, Curtin researchers have found that adding nickel and cobalt to cheaper, previously ineffective catalysts enhances their performance (lowering energy required to split water and increasing yield).

Dr Guohua Jia, who led the study, said the work could have far-reaching implications for sustainable fuel generation in the future.

“Our research essentially saw us take two-dimensional iron-sulphur nanocrystals, which don’t usually work as catalysts for the electricity-driven reaction that gets hydrogen from water, and add small amounts of nickel and cobalt ions. When we did this, it completely transformed the poor-performing iron-sulphur into a viable and efficient catalyst,” he explained. “Using these more abundant materials is cheaper and more efficient than the current benchmark material, ruthenium oxide, which is derived from ruthenium element and is expensive.”

“Our findings not only broaden the existing 'palette' of possible particle combinations, but also introduce a new, efficient catalyst that may be useful in other applications. It also opens new avenues for future research in the energy sector, putting Australia at the forefront of renewable and clean energy research and applications.”

Jia said the next steps will involve expanding and testing the electrocatalyst on a larger scale, in order to assess its commercial viability.

“Only 21 per cent of energy is produced from renewables in the national energy market, which clearly indicates more efforts are required from Australia to make a transition from fossil fuels to clean energy,” Jia said. “But this shift is only possible when the knowledge from the research sector gets translated into real-world solutions and applications in the energy sector.”