Thin films CF04_3
Project costs: 747 T€
Project Period: 05/2022–04/2024
Partners:
Overview:
Solid-state ammonia synthesis (SSAS) is an attractive electrochemical process that enables the production of ammonia directly from water vapor and nitrogen, classically at temperatures around 450–550 °C. In the Spudnik project, metal-supported membrane electron assemblies (MEAs) are produced for solid-state ammonia synthesis. Metal supports are advantageous in terms of stack integration of the cells, as they can be easily electrically contacted and sealed. Due to their high-pressure stability, elevated pressures can be used within the system to increase ammonia synthesis rates. The MEAs consist of a palladium-silver anode, a ceramic electrolyte and a cathode decorated with iron nanoparticles. The principle is to oxidize water vapour at the anode and transport the protons released in the process via the electrolyte to the catalyst, where they reduce the nitrogen to ammonia.
Both anode and electrolyte are deposited as a 1 µm thick layer by magnetron sputtering. This process allows precise control over the composition of the deposited materials. Furthermore, a selective laser treatment is employed in the project forpost-treatment to improve its ionic conductivity without damaging the anode or the metallic substrate. To prevent diffusion between anode and metal substrate during the operation, the substrate is coated with a ceramic protective layer. The cathode layer is produced by spraying a microparticulate dispersion with layer thicknesses of < 30 µm and is also optimized in terms of crystallinity by laser treatment without negatively affecting the porosity. The aim of the project is to surpass previously demonstrated MEAs for solid-state ammonia synthesis in respect of performance and thus further pave the way for the practical implementation of this technology.