Chemistry professor Lee Chan-woo, left, and doctoral students Dwi Sakti Aldianto Pratama, center, and Andi Haryanto / Courtesy of Kookmin University
A research team at Kookmin University has developed a heterostructured catalyst that efficiently promotes hydrogen production in alkaline water electrolysis, the school said Monday.
The team, led by professor Lee Chan-woo of the Department of Chemistry, has successfully identified a mechanism enabling the catalyst to accelerate water-splitting, according to the university.
The team uniformly deposited ruthenium oxide nanoparticles approximately 2 nanometers in size onto 25-nanometer titania supports, creating a heterointerface that rapidly facilitates the water dissociation reaction.
The school noted that anion exchange membrane water electrolysis has attracted attention as a next-generation hydrogen production technology because it operates under alkaline conditions, reducing dependence on expensive platinum-group catalysts and corrosion-resistant components.
However, under alkaline conditions, the initial step of breaking the oxygen-hydrogen bond in water molecules to form hydrogen intermediates proceeds slowly, resulting in high overpotential for the hydrogen evolution reaction and reduced energy efficiency.
To solve the problem, the research team devised a ruthenium–titania heterostructured catalyst by combining ruthenium-based materials, which are seen as alternatives to platinum catalysts, with water-activating titania.
Schematic illustration of the hydrogen production performance and reaction mechanism of the ruthenium-titania heterointerfacial catalyst / Courtesy of Kookmin University
The findings are significant not only for improving catalytic performance, but also for directly confirming how water is activated at the heterointerface.
“This study is meaningful not only because our team has developed a highly active catalyst, but also because the research directly observed the process by which the heterointerface activates water molecules under actual operating conditions,” Lee said.
He added, “Based on the principle that water activation and hydrogen intermediate formation occur in a separated yet cooperative manner at the ruthenium–titania interface, we expect to propose an efficient catalyst design strategy applicable to next-generation alkaline and anion exchange membrane water electrolysis systems.”
The study was published April 27 in the international carbon energy technology journal Carbon Energy under the title “Ruthenium-Titania Interface-Mediated Water Activation for High Turnover Frequency in Alkaline Hydrogen Evolution.”
The research team included doctoral students Dwi Sakti Aldianto Pratama and Andi Haryanto in the university’s chemistry department. The research was supported by the Ministry of Science and ICT.