Discovery of a facile process for H2 production using ammonia as a carrier

April 28, 2017, Oita University
H2 production from ammonia and oxygen triggered at room temperature without external heat input. Credit: Oita University

Hydrogen (H2) has attracted considerable attention as a clean energy source because the only by-product of its reaction with oxygen is water, and high efficiency for energy conversion is achieved when it is combined with fuel cell technologies.

However, low volumetric density and the dangers of transporting and handling H2 are drawbacks for commercial applications. These problems could be eliminated by using as a H2 storage medium (H2 carrier).

H2 produced from ammonia is utilized in fuel cells, engines, and turbines. However, the adoption of ammonia as a H2 carrier, especially for household and transportable devices, has been limited due to the lack of an efficient for producing H2 and nitrogen by ammonia decomposition.

To overcome this limitation, the research team, led by Dr. Katsutoshi Nagaoka and Dr. Katsutoshi Sato, set out to develop a process that could be initiated rapidly, and that could produce H2 at a high rate without the need for external heat.

They found that H2 can be produced by supplying ammonia and oxygen at room temperature to a pre-treated RuO2/γ-Al2O3 catalyst without external heating. The heat evolves by ammonia adsorption onto this catalyst, increasing it to the catalytic auto-ignition temperature of ammonia. Subsequently, production of H2 by oxidative decomposition of ammonia begins. In this process, once the is initiated, it can start again repeatedly even if there is no external heat supply because adsorbed ammonia is desorbed during the reaction.

Dr. Nagaoka said, "Our discovery utilizes a simple fundamental physicochemical process, namely adsorption, to operate a reaction with minimal energy input. We expect this to contribute to the development of efficient, carbon-free energy production and thus to global solutions for energy and climate crises."

Explore further: Flipping the switch on ammonia production: Process generates electricity instead of consuming energy

Related Stories

Recommended for you

Pigments in oil paintings linked to artwork degradation

January 17, 2018

Experts have long known that as oil paintings age, soaps can form within the paint, degrading the appearance of the artworks. The process significantly complicates the preservation of oil paintings—and cultural manifestations, ...

Designing the next generation of hair dyes

January 17, 2018

North Carolina State University researchers have created the largest publicly available chemical database of hair dye substances as a resource for developing a new generation of hair color products that are safer for consumers, ...


Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.