Dr. Woohyun Kim's research team from the Hydrogen Research Department at the Korea Institute of Energy Research (KIER) has successfully developed an innovative nickel-cobalt composite catalyst that can accelerate the production and commercialization of turquoise hydrogen.*
*Turquoise Hydrogen: A technology that produces hydrogen and carbon by decomposing hydrocarbons such as methane (CH₄) (CH₄ → C + 2H₂). Unlike gray hydrogen, the most widely used hydrogen production technology, turquoise hydrogen generates no carbon dioxide emissions during the production process.
In 2021, the Korean government announced the "First Hydrogen Economy Implementation Plan," aiming to supply 28 million tons of clean hydrogen domestically by 2050. Consequently, recent hydrogen research has been actively focusing on production methods that can reduce greenhouse gas emissions.
*Clean Hydrogen: Hydrogen that contributes to carbon neutrality by maintaining greenhouse gas emissions below a certain threshold during production. In the Republic of Korea, hydrogen is classified as clean if the total greenhouse gas emissions during the production of 1 kg of hydrogen are 4 kg or less.
Turquoise hydrogen, a type of clean hydrogen, is a technology that produces hydrogen and solid carbon by thermally decomposing methane (CH₄), the main component of natural gas. While it uses fossil fuels as the source, it does not emit carbon dioxide during the production process. As a result, it eliminates the need for additional carbon dioxide capture and storage, enabling the production of clean hydrogen.
However, the commercialization of turquoise hydrogen technology has been delayed due to challenges in supplying the heat required for the reaction. Catalytic Turquoise hydrogen production typically uses nickel- and iron-based catalysts, which exhibit low activity at lower temperatures, requiring the maintenance of high temperatures around 900°C for stable production. Additionally, the lack of viable applications for the carbon produced alongside hydrogen during the reaction remains an issue that needs to be addressed.
The research team successfully developed an innovative catalyst by adding cobalt to a nickel-based catalyst to overcome the limitations of existing catalysts. Compared to previously studied catalysts, the newly developed catalyst enables hydrogen production with higher efficiency at significantly lower temperature ranges.
Cobalt plays a key role in enhancing electrical activity and improving durability when used as a catalyst in the production of carbon-based materials. Building on this property, the research team added cobalt to a nickel-based catalyst and conducted experiments to optimize its composition and ensure reproducibility. As a result, they found that a composition containing 8% nickel and 2% cobalt achieved the highest hydrogen production efficiency.
The developed catalyst demonstrated over 50% higher hydrogen productivity compared to previously developed catalysts, based on initial activity measured within the first 30 minutes, even at a low temperature of 600°C. Additionally, while the initial activity of existing catalysts is maintained for about 90 minutes, the new catalyst extends this duration by 60%, maintaining its initial activity for approximately 150 minutes.
*Initial Activity: Refers to the active state observed immediately after a catalytic reaction begins and serves as a primary indicator in evaluating the performance of catalyst candidates. A catalyst is considered superior if it exhibits high initial activity and a prolonged maintenance time of that activity.
The team also observed the formation of carbon nanotubes on the catalyst surface after the reaction. Carbon nanotubes are widely used as electrode materials for secondary batteries and as construction materials, among other applications. This finding highlights the potential to produce high-value-added carbon materials alongside hydrogen production.
Dr. Woohyun Kim, the head of the research, stated, "This research demonstrates a groundbreaking outcome, enabling the simultaneous production of hydrogen and carbon nanotubes, achieving both productivity and economic efficiency." He added, "We plan to further research mass-production technology utilizing the developed catalyst, conduct performance evaluations, and secure core material technology and reaction system design capabilities."
This research was conducted with support from the Korea Institute of Energy Research's Research Program and was published in the November 2024 issue of 'Fuel Processing Technology (Impact Factor: 7.2)', a globally renowned journal in the field of chemical engineering.
