Efficient hydrogen production using non-noble metal CoFe-based ammonia decomposition catalyst

Researchers in South Korea have developed a cobalt-iron (CoFe)-based non-noble metal ammonia decomposition catalyst, advancing eco-friendly hydrogen production.

The research team led by Dr. Su-Un Lee and Dr. Ho-Jeong Chae from the Korea Research Institute of Chemical Technology(KRICT) has successfully developed a high-performance ammonia decomposition catalyst by incorporating cerium oxide (CeO₂) into a cobalt-iron-based layered double oxide (LDO) structure. This innovation enables high ammonia decomposition efficiency at lower temperatures.

Ammonia (NH₃) is gaining attention as a carbon-free hydrogen carrier due to its high hydrogen storage capacity and transport efficiency.

However, extracting hydrogen from ammonia requires a high-temperature decomposition process, typically facilitated by catalysts. Ruthenium (Ru) catalysts demonstrate the highest efficiency in this reaction, but their high cost and the need for elevated temperatures pose significant barriers to large-scale application.

To overcome these challenges, the research team developed a CoFe-based non-noble metal catalyst enhanced with cerium oxide (CeO₂). This catalyst offers high ammonia decomposition efficiency at lower temperatures, ensuring cost efficiency and long-term stability.

Advantages of Cerium Oxide Incorporation

∙ Prevents particle agglomeration: Adjusts the surface structure of CoFe-based LDO catalysts, preventing metal nanoparticle sintering.

∙ Enhances catalytic properties: Utilizes Ce³⁺/Ce⁴⁺ redox transitions to modulate the electronic characteristics of the catalyst.

Facilitating the Rate-Determining Step

∙ The rate-determining step in ammonia decomposition is nitrogen recombination-desorption from the catalyst surface.

∙ The newly developed catalyst optimizes this process, significantly accelerating ammonia decomposition even at lower temperatures.

Thanks to these advancements, the catalyst achieved 81.9% ammonia conversion at 450°C, surpassing previous non-noble metal catalysts.

This marks a significant improvement compared to a 2022 nickel-based catalyst, which exhibited only 45% conversion at 450°C.

Furthermore, long-term stability tests at 550°C demonstrated that the catalyst maintained structural integrity and hydrogen production efficiency even after prolonged operation.

The research team aims to further enhance low-temperature hydrogen production efficiency through additional studies, targeting commercialization by 2030.

"This catalyst can be applied to large-scale ammonia-based hydrogen production, hydrogen power plants, hydrogen fueling stations, and maritime industries." Dr. Su-Un Lee stated.

Dr. Yeong-Kuk Lee, President of KRICT, added, "This breakthrough will accelerate the practical implementation of eco-friendly hydrogen production technology and contribute to a sustainable hydrogen economy based on renewable energy."

###

KRICT is a non-profit research institute funded by the Korean government. Since its foundation in 1976, KRICT has played a leading role in advancing national chemical technologies in the fields of chemistry, material science, environmental science, and chemical engineering. Now, KRICT is moving forward to become a globally leading research institute tackling the most challenging issues in the field of Chemistry and Engineering and will continue to fulfill its role in developing chemical technologies that benefit the entire world and contribute to maintaining a healthy planet. More detailed information on KRICT can be found at https://www.krict.re.kr/eng/

This study was published in Chemical Engineering Journal in November 2024. The research was led by Dr. Ho-Jeong Chae at KRICT, with Dr. Su-Un Lee, a researcher at KRICT as the first author.

This research was supported by KRICT's core research program and Renewable Energy Core Technology Development Program, funded by Korean Ministry of Trade, Industry & Energy.