Ammonia as Chemical Energy Carrier: Electro-Catalytic Synthesis and Decomposition

ABSTRACT

The talk focuses on alternative electro- and thermo-catalytic pathways for the production and decomposition of ammonia related to the use of NH3 as carrier of renewable energy.
Recent advances in electrocatalytic ammonia synthesis in proton-conducting ceramic cells (PCCs) are discussed with a focus on iron-based electrodes [1]. The effects of temperature, gas flow, voltage, and electrolyte thickness on electrochemical ammonia synthesis are investigated. To differentiate the various effects and mechanisms contributing to the electrocatalytic formation of NH3, different gas flow configurations are studied. The experimental results demonstrate that NH3 formation is primarily governed by the applied cell voltage, while the current density plays only a minor role. A strong interaction between electroand thermo-catalytic reactions occurs.

Co-feeding H2 at the cathode proved advantageous for optimizing reaction conditions and increasing ammonia synthesis rates to values of 3×10−8 mol s−1 cm−2 using a PCC with an ironbased electrode of an active area of 12.57 cm².

Also, decomposition of NH3 to H2 can be conducted in PCC. In all cases both electro- and thermos-catalytic processes have to be understood [2]. The combination of thermo-catalytic and electrochemically supported ammonia synthesis and decomposition opens new pathways for the electrification of NH3 production using the rather inexpensive material iron and the use of NH3 as hydrogen carrier.

[1] P. Blanck, E.P. Martin, D. Schmider, J. Dailly, R.J. Kee, O. Deutschmann. Electrochemical Ammonia Synthesis in a Proton-conducting Ceramic Cell: A Parameter Study of an Iron-based Electrode. J. Electrochem. Soc. (2025) DOI: 10.1149/1945-7111/adfc9e.
[2] S. Davari, R. Chacko, T. Bastek, P. Lott, J. Dailly, S. Angeli, O. Deutschmann. Experimental and
Microkinetic Investigation of Thermo-Catalytic Ammonia Decomposition over a Ba-promoted Ru/Ni-
BCZY Catalyst for Use in Ammonia-fed Protonic Ceramic Cells. Appl. Catal. A. 708 (2025) 120571.
DOI:10.1016/j.apcata.2025.120571.

BIO

Olaf Deutschmann, Chair of Chemical Technology at the Karlsruhe Institute of Technology (KIT), works on the development of climate- and environmentally-friendly chemical technologies including carbon capture, carbon-free chemical energy carriers, emission control, fuel and electrolysis cells, circular economy, and digitalization tools in catalysis and reaction engineering. The software packages DETCHEM, CaRMeN, and Adacta were developed under his guidance.
Deutschmann studied physics and chemistry in Magdeburg, Berlin, and Heidelberg earning his PhD from Heidelberg University in 1996. He worked as Postdoc at the University of Minnesota and at Los Alamos National Laboratory. After receiving the venia legendi in physical chemistry from Heidelberg University, he joined the Faculty of Chemistry at the University of Karlsruhe (now KIT) in 2003.
Deutschmann is the founding director of both the Emission Control Center and the Energetic Materials Lab in Karlsruhe, and a founding partner of the start-ups chemogy GmbH and omegadot GmbH. He has published more than 300 papers, books, and patents, and has supervised over 60 PhD students.
Deutschmann also organizes the biannual MODEGAT conference series and serves on several editorial and corporate advisory boards.