Supported catalyst design for low-temperature hydrogen production

A new catalyst strategy developed at Institute of Science Tokyo uses BaSi₂ as a support for nickel and cobalt to decompose ammonia at lower temperatures. By forming unique ternary transition metal–nitrogen–barium intermediates that facilitate nitrogen coupling, the system lowers the energy barrier for ammonia decomposition. This enables nickel- and cobalt-based catalysts to achieve high hydrogen-production activity at reduced temperatures, matching the performance of ruthenium while relying on Earth-abundant metals for cleaner hydrogen generation.

As the world turns towards cleaner energy sources, hydrogen has emerged as a promising alternative to fossil fuels. Hydrogen can be obtained from various sources such as natural gas, water, biomass, and hydrogen-rich carriers. Ammonia is one such source attracting growing attention as an efficient hydrogen carrier because it stores large amounts of hydrogen and is easier to transport. However, releasing hydrogen from ammonia is typically challenging, as it either requires precious metal catalysts such as ruthenium or non-precious metal catalysts operating at very high temperatures.

Addressing this challenge, a team of researchers led by Dr. Qing Guo and Dr. Shiyao Wang, together with Professor Masaaki Kitano and Specially Appointed Professor Hideo Hosono from the MDX Research Center for Element Strategy, Institute of Integrated Research, Institute of Science Tokyo, Japan, developed a new catalyst design strategy for ammonia decomposition. Instead of solely relying on the catalyst metal, this strategy focuses on using barium silicide (BaSi₂) as an active support that directly participates in the catalytic process. The study was published online in the Journal of the American Chemical Society on February 19, 2026.

A typical ammonia decomposition reaction involves several steps, beginning with the adsorption of ammonia onto the catalyst surface, followed by the stepwise removal of hydrogen atoms and coupling of the remaining nitrogen atoms to form nitrogen gas. Conventional non-precious metal catalysts often struggle with the nitrogen–nitrogen coupling step, which is the slowest stage in the reaction.

To overcome this, the researchers used BaSi₂, a stable compound with low-valence barium atoms capable of donating electrons. When used as a support with metals like nickel, it donates electrons to nitrogen atoms bound to the metal surface. This results in the formation of ternary transition metal–nitrogen–barium intermediates that stabilize the reaction’s transition state during nitrogen–nitrogen coupling and significantly reduce the energy required for the reaction.

“We aimed to uncover how the support could actively cooperate with the metal to remove the long-standing kinetic barrier in ammonia decomposition,” says Kitano.

Using spectroscopic techniques, the researchers confirmed the presence of these intermediates at the catalyst interface between the metal and the support. Additionally, computational analyses showed that they significantly reduced the energy barrier for the nitrogen coupling reaction compared to conventional nickel surfaces. This resulted in an impressive catalytic performance of more than 99% ammonia conversion at 540 °C, outperforming similar catalysts at notably lower temperatures.

Surprisingly, the same effect was also observed with cobalt, suggesting that the approach could be broadly applied to other non-precious metals as well.

“Our approach offers an alternative perspective on metal–support synergy and opens a new way towards high-performance catalysts made from Earth-abundant materials,” explains Kitano.

Ruthenium catalysts are currently among the most effective catalysts for ammonia decomposition, but they are costly and limited in supply. By achieving a performance equivalent to that of ruthenium, the newly developed catalyst offers an affordable and scalable alternative for hydrogen production without relying on precious metals.

Beyond ammonia decomposition, the study demonstrates how catalyst supports can actively shape chemical reactions. By designing supports that participate directly in reactions, researchers could develop more efficient technologies not only for hydrogen generation but also for other sustainable chemical processes. As research continues, strategies like this could accelerate the shift toward cleaner energy systems while reducing dependence on rare resources—paving the way for a more sustainable future.

***

About Institute of Science Tokyo (Science Tokyo)

Institute of Science Tokyo (Science Tokyo) was established on October 1, 2024, following the merger between Tokyo Medical and Dental University (TMDU) and Tokyo Institute of Technology (Tokyo Tech), with the mission of “Advancing science and human wellbeing to create value for and with society.”