Due to the increasing demand to lessen carbon emission, green hydrogen has become significant in recent years. This technology involves the production of hydrogen without using fossil fuels or carbon dioxide. However, it was not economically feasible since the water electrolysis devices needed to produce green hydrogen have high production cost.
One way to solve this problem is by developing a technology that can lessen the amount of rare metals, such as iridium and platinum, which are used in making polymer electrolyte membrane.
Development of a Highly Active Water-Oxidizing Anode
This proposal was made possible by Dr. Hyun S. Park and Sung Joong Yoo from the Hydrogen and Fuel Cell Research Center at the Korea Institute of Science and Technology (KIST). They focused on developing a highly active water-oxidizing anode that relies in a core-shell catalyst structure.
Past studies involved the reduction of iridium catalyst while securing platinum and gold as the electrode protection layer. In the research made by Park and Yoo, they substituted the precious metal with cheap iron nitride that has large surface area. Then, the top layer was coated with a small amount of iridium catalyst to increase the economic efficiency of the proton-exchange-membrane water electrolyzer (PEMWE).
Replacing gold and platinum as protective layer for the oxygen electrode in polymer electrolyte membrane hydrogen production devices requires a process that coats electrode with iron oxide. This was followed by the conversion of iron oxide to iron nitride for increased electrical conductivity.
The team did not only reduce the amount of iridium and platinum in the electrode protection layer, but their technology also demonstrates high performance and durability. The alternative electrode developed by the scientists to protect oxygen generating electrode demonstrates similar level of performance compared to existing electrolysis units in the market. It also lessens the amount of iridium catalyst to 10% of the existing quantity while enabling the device to operate for over 100 hours for verification of initial stability.
Potential of Green Hydrogen Technology
Green hydrogen involves converting electrical energy into chemical energy using the process of electrolysis. In the past, the use of hydrogen was limited to the production of greener vehicles. As electric vehicles have proven to be more eco-friendly, experts expressed their interest in using hydrogen to other industries.
Hydrogen has been proven to be a versatile carrier of energy which can be generated from multiple feedstocks. As renewable electricity is converted to hydrogen, electrolyzers are allowed to provide flexibility to the grid.
Experts believe that this technology could provide the key in the global transition to sustainable source of energy. It lessens the demand for fossil fuel energy sources, which cause harm by releasing vast amounts of carbon dioxide in the air. Hydrogen can also be used as alternative to diesel in powering generators for energizing future data centers.
According to the International Energy Agency (IEA), about 830 million tons of carbon dioxide will be saved from being emitted every year when compared to gas production using conventional fossil fuel technologies. As of now, some countries in Europe and the U.S. have started their major green hydrogen developments and investments.
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