The Korea Institute of Science and Technology (KIST)‘s Hydrogen and Fuel Cell Research Center’s researchers have announced a revolutionary invention that could slash the cost of producing green hydrogen. Green hydrogen is made by using renewable energy to electrolyze water. It’s a key part of the battle for sustainable restructuring in terms of the energy future. The team’s innovative approach substitutes iron nitride (an inexpensive substitute for precious metals) for the electrode protective layer, providing an opportunity to improve economic performance of electrolysis machines.
It has always been an obstacle to making green hydrogen when using pricey, precious metals such as iridium and platinum in the electrode protective layer. Other previous research efforts have tried to reduce the quantity of iridium catalyst while leaving high levels of platinum and gold in the sacrificial layer. But the most recent study, led by Sung Jong Yoo and Dr. Hyun S Park takes a different approach.
The study team substituted iron nitride, a cheap material of wide surface area for the pricey metal in the electrode protective layer. A thin layer of iridium catalyst was then applied evenly on top of this. This is a strategic innovation which enhances the economic efficiency of the electrolysis device without compromising its function or durability. But the green hydrogen economy hinges on whether or not any electrolysis device is economically viable in areas where industrial-grade products require high purity hydrogen, such as chemicals and steelmaking.
The polymer electrolyte membrane water electrolysis apparatus constructed by the researchers, which uses energy from renewable sources such as solar power to generate high-purity hydrogen and oxygen through breaking down water is an indispensable part of this process. They also operate as efficient renewable energy storage devices, so the importance of raising their economic efficiency is obvious for a wider application of green hydrogen technologies.
In an electrolysis system, the oxygen-generating electrode is often coated with precious metals (such as gold or platinum) to protect it. But the amounts these metals are mined at and their high manufacturing costs put a pretty big damper on green hydrogen generating devices’ scalability. A procedure devised by the research team uses less than 0.1 mg/cm2 of iridium catalyst, coating an evenly thin layer on top of the iron nitride protection plate at a depth only 25 nanometers thick.
Dr. Hyun S. Park at KIST says that the study is important because in order for polymer electrolyte membrane green hydrogen production devices to become economical and widespread, it must be possible not only reduce by a lot the amount of iridium catalyst used (to something like 20 ppm), but there also needs to find cheaper materials with which we can
The positive results of the research provide hope for an environmentally and economically feasible future in terms of green hydrogen production. And the ultimate goal is to transfer this technology into commercial products in a short time, which requires more testing of performance and durability for the electrode. This could have a major impact on the green hydrogen economy, offering consumers and businesses alike an alternative that’s cheaper in terms of money as well as nature.
