Ammonia on demand: Catalytic N2 reduction on photo-charged tailored TiO2 aerogels

Roland Marschall, University of Bayreuth; Barbara Milow, German Aerospace Center (DLR), Cologne; Dirk Ziegenbalg, Ulm University

In the present project, a concept for a sustainable and inexpensive process to generate ammonia on-demand is systematically investigated. This project will present a strategy to charge and store electrons upon light irradiation in a nanostructured semiconductor (TiO₂ aerogels), which can be then discharged in the dark with N₂ to form ammonia catalytically. This enables the production of ammonia on demand at any time. Moreover, a reactor concept will be developed to perform and investigate the on-demand ammonia synthesis in a decentralized way. This reactor allows for a separation of light-harvesting and the actual N₂ reduction, enabling an independent investigation of the reaction conditions for each reaction step. Furthermore, the possibility of intermediate storage of a photocharged aerogel opens up degrees of freedom for the design of the N₂ reduction reactor, which can beneficially be utilized for the design of efficient chemical plants that produce fertilizers on-site and on-demand.