According to projections from the International Energy Agency (IEA), global demand for hydrogen is anticipated to surge to 530 million tons by 2050, marking a nearly six-fold increase from the levels seen in 2020.
At present, the predominant method for hydrogen production involves the reaction of natural gas and water vapor, yielding what’s known as gray hydrogen, largely due to its significant carbon dioxide emissions. This gray hydrogen accounts for approximately 80% of the total hydrogen production. In stark contrast, green hydrogen is generated through water electrolysis using electricity, with zero carbon dioxide emissions. Nevertheless, a notable challenge lies in the costly use of precious metal catalysts, such as iridium oxide.
A research team, spearheaded by Dr. Yoo Sung Jong at the Hydrogen and Fuel Cell Research Center of the Korea Institute of Science and Technology (KIST), has achieved substantial cost reduction in green hydrogen production. They achieved this by employing an anion exchange membrane water electrolysis device with exceptional performance and longevity, thanks to the incorporation of a carbon support.
Carbon supports have been harnessed in various electrocatalyst applications because of their excellent electrical conductivity and specific surface area. Nonetheless, their usage has been constrained by their tendency to oxidize into carbon dioxide under water electrolysis conditions, particularly at high voltages and in the presence of water.
The research team synthesized a more cost-effective alternative to iridium, a nickel-iron-cobalt layered double hydroxide material, on a hydrophobic carbon support, using it as an electrocatalyst for the oxygen evolution reaction in anion exchange membrane electrolysis. This catalyst exhibited remarkable durability, attributed to its layered structure interfacing with the hydrophobic carbon support and the nickel-iron-cobalt layered double hydroxide catalyst.
Regarding carbon corrosion, the generation of carbon dioxide during the corrosion process was found to be reduced by over 50%, primarily due to decreased interaction with water, a pivotal factor in carbon corrosion.
As a result of performance evaluations, the newly-developed catalyst support achieved a current density of 10.29 A/cm2 in the 2 V region, surpassing the 9.38 A/cm2 current density of commercial iridium oxide. Moreover, it displayed long-term durability, enduring for about 550 hours. The researchers also identified a correlation between electrolysis performance and the hydrophobic nature of carbon, highlighting, for the first time, the significant impact of support hydrophobicity on the water electrolysis device’s performance.
Dr. Yoo Sung Jong at KIST stated, “The outcomes of this research underscore the potential of water electrolysis devices utilizing carbon supports, which were previously limited due to corrosion concerns. Expanding research focused on catalyst development for various supports could propel water electrolysis technology to the next level.”
Dr. Yoo Sung Jong Yoo further emphasized, “We are committed to advancing a range of eco-friendly energy technologies, including the production of green hydrogen.”
Source: Korea Institute of Science and Technology
