After a report from the International Energy Agency (IEA) stated that by 2050, global hydrogen demand is expected to rise by 530 million tons, which is almost 6 times its 2020 levels, researchers began looking into a way the current issues around hydrogen production today could be solved to meet this demand for hydrogen.
Dr. Yoo sung Jong and his research team from the Hydrogen and Fuel Cell Research Centre at the Korea Institute of Science and Technology (KIST), has made an excellent breakthrough by discovering a way to make a significant reduction to the production cost of green hydrogen.
The current method for producing hydrogen involves combining natural gas and water vapour to yield ‘gray hydrogen’ which is distinctly known for emitting substantial amounts of carbon dioxide and contributing to approximately 80% of total hydrogen output. Green hydrogen is much more environmentally friendly as it is the carbon dioxide-free alternative, which is made possible as it is generated via water electrolysis powered by electricity. The remaining issue with green hydrogen production is that the process needs a costly catalyst such as iridium oxide to work. This is what Dr. Jong’s research team have focused on improving, and they now have a solution which enhances the catalysts performance and durability.
By incorporating carbon support into an anion exchange membrane water electrolysis device, the performance and durability are enhanced. Previously carbon supports were not often used for this process as they often oxidise into carbon dioxide when under high voltage and water-rich electrolysis conditions. However, carbon supports are favoured for their electrical conductivity properties and significant surface area, therefore the research team overcame the issues around carbon support by synthesising a nickel-iron-cobalt layered double hydroxide material, which has the advantage of being more cost-effective than iridium. The next step involved applying the material onto a hydrophobic carbon support and used this as an electrocatalyst for the oxygen evolution reaction in anion exchange membrane electrolysis.
The results showed that the catalyst portrayed excellent durability due to its layered structure that interfaces with a hydrophobic carbon support and the nickel-iron-cobalt layered double hydroxide catalyst. Another benefit of the catalyst was that carbon dioxide production throughout the corrosion process had a 50% reduction rate. Results depicted that this reduction was created from a decreased interaction with water, which is an essential part of carbon corrosion. Looking at the performance evaluation, the research team saw that the newly developed supported catalyst achieved a current density of 10.29 A/cm-2 in the 2 V range, surpassing the 9.38 A/cm-2 current density achieved by commercial iridium oxide. It also expressed long-term durability as it sustained its performance for around 550 hours.
It was also made clear through the results that there was a definite correlation between the electrolysis performance and the hydrophobicity of the carbon support. This is an incredibly significant breakthrough as it demonstrated that the support’s hydrophobic nature does significantly impact the performance of a water electrolysis device. This portrays how the breakthroughs discovered within this experiment, will reduce the cost of producing green hydrogen through how well the catalyst performed and the way its durability was enhanced. This new method will also enable the reduction of carbon emissions as the lower cost and benefits of the method will make this process realistically available for more commercial use in the production of green hydrogen in the future.