Researchers in Korea have developed the’anion exchange membrane seawater electrolysis technology’ for the first time in Korea, which can dramatically reduce the cost of hydrogen production by directly producing green hydrogen using seawater, the most abundant water resource on the planet.
Materials Research Institute of Korea develops high-performance anion exchange membrane seawater electrolysis technology
The Korea Institute of Materials Research (KIMS, President Jeong-Hwan Lee), a government-funded research institute under the Ministry of Science, Technology, and Communication, is a research team from Seung-mok Choi and Ji-Hoon Lee in the Energy and Electronic Materials Laboratory. And succeeded in producing high-purity hydrogen by electrolyzing the most abundant seawater on the planet.
Among the water electrolysis technologies suitable for the production of green hydrogen,’anion exchange membrane water electrolysis’ is a technology that safely produces high-purity hydrogen at low cost using an inexpensive non-precious metal catalyst.
However, since purified water (ultra-pure water) must be used for hydrogen production, it has been the cause of increasing the hydrogen production cost as well as hindering the expansion of the water electrolysis base.
The research team developed a catalyst-integrated electrode by directly forming an iron hydroxide (FeOOH) catalyst in the form of a highly selective two-dimensional nanosheet doped with nickel (Ni) on the electrode surface. Through this, the oxygen generation reaction overvoltage and the material transfer resistance were reduced, and by applying and optimizing this electrode to the anion exchange membrane water electrolysis, it was possible to secure high hydrogen generation efficiency by suppressing the chlorine generation reaction.
In general, if seawater is directly electrolyzed to produce hydrogen, hydrogen can be obtained from the cathode, but at the opposite anode, chloride ions contained in seawater are oxidized to generate chlorine, and water is oxidized to generate oxygen. The’oxygen evolution reaction’ that occurs will take place competitively. At this time, the electrode surface is
Locally, there is an acidic atmosphere, and for this reason, there is a disadvantage that the material must be used as an electrode catalyst material, such as expensive precious metals (platinum (Pt), iridium (Ir), palladium (Pd), etc.) that are stable in acid.
However, the research team controlled the pH of seawater (pH, the hydrogen ion concentration index of the solution) to increase the potential at which the chlorination reaction occurs from 1.36V (vs.RHE) to 1.72V (vs.RHE) to suppress the reaction and develop development. The use of non-precious metal catalyst materials is possible by applying a highly active catalyst to reduce overvoltage and lead the oxygen generation reaction to take place.
“We have opened a way to produce high-purity hydrogen from seawater inexpensively through the non-precious metal-based anion exchange membrane seawater electrolysis technology,” said Seungmok Choi, the research director. “If it is produced, we expect to create a new business model where hydrogen can be directly charged to hydrogen vessels offshore.”
This research achievement was carried out with the support of the hydrogen energy innovation technology development project of the Ministry of Science and ICT and the major projects of the Korea Institute of Materials Research.The research results were published in the Journal of Materials Chemistry of the Royal Society of Chemistry (RSC). A, 1st author Park Yoo-se, Dr. Joo-young Lee) was published as the cover paper on March 3rd.
The research team is currently conducting an empirical study of applying the results of this study to an anion exchange membrane seawater electrolysis system.
Online JoongAng Ilbo
