A research team from the University Alliance Ruhr has found a catalyst that can convert ammonia into the energy carrier hydrogen and into nitrite, which can easily be processed into fertilizer. Until now, these were separate chemical processes.
A new catalyst developed by researchers at the Ruhr University Bochum (RUB) converts ammonia into the energy carrier hydrogen and nitrite. This in turn can easily be processed into fertilizer. The experts present details in “Angewandte Chemie International Edition”.
Haber Bosch reversed
“We therefore had the idea of combining the reverse Haber-Bosch reaction with a second electrolysis of water and, instead of nitrogen, producing a product that can easily be used to produce fertilizer, such as nitrite or nitrate,” explains RUB scientist Ieva Cechanaviciute, explaining the approach.
In this reaction, ammonia and water are used to produce nitrite and hydrogen. Unlike in the reverse Haber-Bosch reaction, the hydrogen output is doubled and instead of unusable nitrogen, mainly nitrite is produced, which can be further processed into fertilizer.
An energetic gradient
Gas diffusion electrodes were used for the reaction, into which ammonia was fed as a gas. One challenge for the researchers was to find a suitable catalyst with which their idea could be implemented. This is because the energy gradient means that the starting materials tend to convert into nitrogen and not into nitrite.
In previous work, the RUB scientists had already experimented with multi-metal catalysts that proved suitable for this purpose. They were able to convert 87 percent of the gaseous ammonia into nitrite. The team also managed to avoid oxygen as an undesirable byproduct of water electrolysis.
Source: www.com-magazin.de
