Exploring the Feasibility of Electrochemical Ammonia Synthesis: From Lab-Scale to Production Plant

Ammonia can be used as a global energy carrier to connect the geographically divided landscape of renewable energy sources. Unfortunately, the current ammonia production process of the century old fossil-fuel based Haber-Bosch process is not sustainable and is responsible for approximately 1.2% of the global anthropogenic CO2 emissions. The most polluting part of the process is the hydrogen generation step by either coal gasification or the more common steam methane reforming. The majority of the emissions can be cut down by replacing this step by water electrolysis o en referred to as the electrified Haber- Bosch. An alternative technology for sustainable ammonia production, which is still in its infancy, is ammonia synthesis via the electrochemical reduction of nitrogen (NRR), requiring a proton source and electrons from renewable electricity. The following NRR approaches are prominently reported in the literature: (i) NRR in aqueous based electrolytes at ambient conditions (aqueous NRR), (ii) NRR at elevated temperatures with a solid oxide electrolyte, (iii) Li-mediated NRR in non-aqueous electrolytes at room temperature (Li-NRR). The main aim of this thesis is to identify and understand which of the above-mentioned electrochemical ammonia routes are the most promising for future application...