N2Red: Investigation of photocatalytic and photothermocatalytic ammonia production from molecular nitrogen and water under elevated temperature and pressure conditions

Motivation

Nitrogen is an essential component of many chemical compounds. Most of the nitrogen fixation takes place through reduction to ammonia, which finds a variety of applications, e. g. through further processing into fertilisers or plastics.

In the chemical industry, ammonia is nowadays mainly produced by the Haber-Bosch process. Apart from the large quantities of hydrogen required, this is also a very energy-intensive process. The development of sustainable production methods with lower energy consumption is essential for the future.

In this project, molecular nitrogen is to be reduced to ammonia using a photocatalytic approach. The required electrons will be provided by the simultaneous oxidation of water. By analyzing both reactions, optimal reaction conditions for potential photocatalysts shall be identified.

Some photocatalysts are also capable of reducing protons to hydrogen, with the required reduction potential being very close to that of nitrogen reduction. Therefore, the water splitting activity will also be evaluated. If this is more pronounced than the nitrogen reduction, it will also be investigated whether the hydrogen produced is suitable for in situ thermo- or photocatalytic ammonia production at elevated temperatures and pressures.

In collaboration with the Technical University of Darmstadt, self-synthesized bismuth oxyhalide-based photocatalysts will be tested for their suitability to produce ammonia.

Das Forschungsprojekt wird über die DFG im Rahmen des Schwerpunktprogramms "Nitroconversion: Verknüpfung von Katalysatoren, Mechanismen und Reaktorkonzepten für die Umwandlung von Distickstoff durch elektrokatalytische, photokatalytische und photoelektrochemische Methoden" (SPP2370) gefördert.