Development of Efficient Synthesis Scheme of High-Efficiency Single-Atom Catalyst for Hydrogen Production by Water Electrolysis
The results from Professor Moon Jun-hyuk’s group were published in Chemical Engineering Journal.

▲ Professor Moon Jun-hyuk of the Department of Chemical and Biological Engineering and the School of Smart Mobility.

The research group led by Professor Moon Jun-hyuk (Department of Chemical and Biological Engineering and the School of Smart Mobility) developed an electrochemical catalyst for water electrolysis, which allows for highly efficient hydrogen production.

The study was led by Professor Moon’s group and participated in by the Brookhaven National Laboratory. The results were published only in Chemical Engineering Journal (IF: 15.1, top 3.51%), one of the best chemical engineering journals, on April 3.
*Title of article: Amorphous-Crystalline Transition-Driven Synthesis of Co Single-Atom Catalysts on MoO3 for Enhanced Hydrogen Evolution in Acidic and Alkaline Media
* Link DOI: https://doi.org/10.1016/j.cej.2024.150976

Green hydrogen production is drawing attention as a sustainable energy solution that does not emit carbon dioxide. One of the most representative technologies is water electrolysis, which produces hydrogen by electrolyzing water, for which an electrochemical catalyst to promote the reaction is essential. In order to commercially utilize this technology, efforts are being made to reduce the use of expensive precious metal catalysts. To this end, 'single-atom catalysts' that maximize precious metal utilization by individually scattering precious metal atoms on the surface of a support, are drawing much attention.

In this study, the research group synthesized a catalyst in which cobalt single atoms were impregnated on a molybdenum oxide support. In other words, non-precious metal single atoms were used. The research group found through simulation that water electrolysis activity may be greatly enhanced by the interaction of molybdenum oxide, even with single atoms of the non-precious metal cobalt.

The research group used the phase transition phenomenon from amorphous to crystalline molybdenum oxide in forming the single-atom catalyst. In other words, a stable single-atom catalyst could be easily formed through a crystallization process in which the loose lattice structure of the amorphous form was impregnated with single atoms and the lattice structure was tightened.

The research group confirmed excellent electrochemical hydrogen evolution reactions in both acidic and basic solutions using the cobalt single-atom/molybdenum oxide catalysts. All of the catalysts exhibited hydrogen evolution reactivity and stability with a low overvoltage of 0.1 V.

Professor Moon, the corresponding author of the article, commented, “The significance of this study is that we presented an easy and efficient method of forming a single-atom catalyst of a nonmetallic element, and we achieved high stability and highly efficient reactivity in both acids and bases.”

This study was supported by the Ministry of Science and ICT.

<Figure 1>

▲ (Top) Process of preparing cobalt single-atom/molybdenum oxide catalysts by amorphous-to-crystalline phase transition;  

    (Bottom) An electron microscope image of a cobalt single-atom/molybdenum oxide catalyst.

<Figure 2>

▲ Production of hydrogen by water electrolysis using a cobalt single-atom/molybdenum oxide catalyst.