A technology that maintains high hydrogen production efficiency over a long period by leveraging semiconductor technology capable of implementing a three-dimensional network structure has been developed.
On Sept. 25, the Korea Advanced Institute of Science and Technology (KAIST) announced that a joint research team consisting of Professor Jung Yeon-sik from the Department of Materials Science and Engineering, Dr. Kim Jin-young from the Korea Institute of Science and Technology (KIST), and Dr. Kim Dong-hun have developed a high-efficiency and highly durable hydrogen production technology. This technique utilizes a novel principle in which the hydrogen production catalyst, which typically loses electrons during its reaction, receives replenishment from a new concept oxide semiconductor.
To produce high-purity green hydrogen, an environmentally friendly polymer electrolyte membrane water electrolysis (PEMWE) device, which electrolyzes water using renewable energy, is utilized. For efficient and durable hydrogen production, it’s imperative that the iridium (Ir) catalyst, which is commonly used, continuously maintains a state with many electrons. However, there was a chronic problem where the efficiency and lifespan significantly decreased due to the catalyst reaction’s nature, which easily loses electrons and gets oxidized.
The joint KAIST-KIST research team employed semiconductor technology that allows for the implementation of a three-dimensional network structure by stacking ultra-fine patterns. The material used was tin oxide doped with antimony (Sb), and the team applied semiconductor deposition technology to ensure that oxygen ions, which act as an “electron reservoir,” were densely distributed on the oxide surface. When this unique oxide semiconductor is used as a catalyst support, the oxygen ions located on the surface continuously replenish the Ir catalyst with a sufficient number of electrons, maintaining the catalyst’s high hydrogen production efficiency for an extended period.
When applied to the polymer electrolyte membrane water electrolysis (PEMWE) device, the research team achieved a performance improvement of up to 75 times compared to conventional commercial Ir nanoparticle catalysts. At the same time, they also secured outstanding durability during prolonged operation at high current densities.
This study, in which Lee Kyu-rak from KAIST’s Department of Materials Science and Engineering, Dr. Kim Joon and Dr. Hong Doo-seon from KIST participated as co-first authors, was published in the international academic journal Nature Communications on Sept. 5. The paper is titled “Efficient and sustainable water electrolysis achieved by excess electron reservoir enabling charge replenishment to catalysts.”