A research team led by Lee Yong-geol, a professor in the Department of Chemical Engineering at Dankook University, has developed a water electrolysis electrode catalyst with high activity and durability using non-precious metals — nickel, cobalt and iron — the university said Wednesday.
Water electrolysis is an eco-friendly technology that produces hydrogen by splitting water using electricity. The oxygen evolution reaction, or OER, is particularly energy-intensive, making high-performance catalyst development a key factor in determining hydrogen production efficiency.
Conventional precious metal catalysts based on ruthenium and iridium deliver strong performance but are expensive and scarce, limiting large-scale commercialization. Nickel-based catalysts, which have drawn attention as an alternative, have long suffered from structural degradation and declining performance after extended use.
The research team addressed this by electrochemically restructuring the surface of a nickel-cobalt-iron alloy to create a "hierarchical structure" — a porous active layer inside the catalyst that conducts electricity efficiently and promotes vigorous surface reactions.
The team combined real-time X-ray analysis with computational science to identify, at the atomic level, the mechanisms behind the catalyst's improved performance and durability. The study revealed that the stable transformation and recovery of the nickel active phase during oxidation-reduction cycles, along with the suppression of iron leaching, are the key principles sustaining the catalyst's high activity and long-term durability.
The catalyst outperformed conventional nickel-iron catalysts (NiFe-LDH) at higher current densities and showed a turnover frequency roughly seven times higher than that of conventional metal alloys.
The catalyst also maintained strong durability in repeated operation tests simulating the unstable power supply of renewable energy sources such as solar and wind. Its high performance in the urea oxidation reaction, in addition to the OER, suggests it could find broad application in next-generation eco-friendly hydrogen production technology.
"This research is significant in that it used a combination of real-time X-ray absorption spectroscopy and computational science to identify, at the atomic level, the mechanisms by which the activity and stability of multi-component non-precious metal catalysts are enhanced," Lee said. "We expect the findings to be applied not only to large-capacity water electrolysis systems and urea-based eco-friendly hydrogen production technology, but also to the design of catalysts for a wide range of electrochemical energy conversion applications."
The findings were published online Aug. 3 in the international journal Small, which carries an impact factor of 12.1.
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