Scientists led by NTU Singapore identify new catalysts for more efficient water splitting

A team of scientists led by NTU Singapore have discovered the parameters that determine the efficiency of a class of low-cost catalysts called spinel oxides – a discovery that breaks a bottleneck in the extraction of hydrogen from water through electrolysis, the process of splitting water with electricity.

A major challenge of this process lies in the energy loss as the chemical reactions involved in water electrolysis take place, driving up the cost to produce hydrogen through this method. Catalysts are therefore necessary to speed up these chemical reactions.

Spinel oxides, which are typically made of cheap transition metals, have garnered interest in recent years as a stable, low-cost catalyst that could overcome this challenge, but the design of high-performing spinel oxides has been hampered by the lack of understanding of how they work.

Now, NTU Singapore’s Associate Professor Jason Xu Zhichuan and his team have made two important advances. They have unravelled, at the atomic scale, how spinel oxides work to speed up water electrolysis. Primed with that new understanding, the team then used machine learning to select new spinel oxides with increased catalytic activity, making water electrolysis more efficient.

These findings bring the team a step closer to making water splitting a suitable approach for large-scale manufacture of hydrogen gas, which has been highlighted by the Energy Market Authority as one possible low-carbon alternative for reducing Singapore’s carbon footprint as it targets to halve its peak greenhouse gas emissions by 2050.