Abstract

Activating molecular nitrogen is an extremely important process as it supplies, in the form of fertilizer, the nitrogen that is a prerequisite for building all amino acids and nucleic acids essential for life. Ammonia is also considered being an energy vector for storing energy over longer time. It shall be motivated why an alternative route to the current thermal ammonia synthesis route – the commercial Haber-Bosch process - could be attractive in a decentralized electrified society. This will be extended to new routes of promotion of thermal ammonia synthesis (and decomposition) showing how cobalt can also be made very active¹. The active site will be identified by a combination of cobalt single crystals with and without steps combined with reaction over mass-selected nanoparticles made in situ by a cluster source². We shall also discuss the briefly the cracking of ammonia for making it useable for the shipping industry using dry³ or wet ammonia⁴. In the second part, we shall turn to electrochemical ammonia synthesis where we now have shown how one can make ammonia at ambient conditions. The Li-mediated process will be discussed, and we will show how we over the last 5 years have gone from having a process that did only make very little ammonia3 to now being capable of obtaining more than 80% Faradaic efficiency and high current densities.^5,6 The scale-up approach will be discussed making grams of ammonia just as characterization of in situ measurements of the dynamic assembly of the solid electrolyte interface (SEI) layer - known from the Li batteries field - is formed, controlling the transport processes.⁷ Despite excellent recent progress there are still substantial outstanding questions concerning energy efficiency which will also be discussed^8,9,10.

References

[1]  Cao, V.,. I. Chorkendorff, J. K. Nørskov, Nature Comm. 13 (2022) 2382. DOI:10.1038/s41467-022-30034-y.

[2]  K. Zhang, ….J. K. Nørskov, I. Chorkendorff, , Science 383 (2024) 1357-1363, DOI: 10.1126/science.adn0558.

[3]  Gunnarson,…..I. Chorkendorff,  Energy & Environmental Science 17 (2024) 9313 – 9322, DOI: 10.1039/d4ee02874k.

[4]  Gunnarson,…. I. Chorkendorff, ACS Energy Letters 10  (2025) 3383‚àí3387. DOI:10.1021/acsenergylett.5c01389

[5]  S. Z. Andersen,… J. K. Nørskov I. Chorkendorff, Nature, 570 (2019) DOI: 10.1038/s41586-019-1260-x

[6]  X. Fu, ... J. K. Nørskov, and I. Chorkendorff, Science 379 (2023) 707-712. DOI: 10.1126/science.adf4403

[7]  S. Li, …. J. K. Nørskov, and I. Chorkendorff, Nature (2024). DOI:10.1038/s41586-024-07276-5

[8]  N. Deissler,‚.. I. Chorkendorff  Energy & Environmental Science, 17 (2024) 3482 - 3492, DOI: 10.1039/D3EE04235A

[9]  S. Li, X. Fu, J. K. Nørskov, I. Chorkendorff, Nature Energy 9 (2024) 1344-1349, DOI: 10.1038/s41560-024-01622-7.

[10]  Y. Zhou, X. Fu, I. Chorkendorff, J. K. Nørskov, ACS Energy Letters 10 (2025) 128-132. DOI: 10.1021/acsenergylett.4c02954  Photo     

Biography

Ib Chorkendorff is Professor in Heterogeneous Catalysis at DTU-Physics. He earned his PhD in 1985 Odense University Denmark, and after a postdoc at University of Pittsburgh, USA, he was employed in 1987 at DTU where he became full professor in 1999. From 2005-2016 he was director of Danish National Research Foundation Center for Individual Nanoparticle Functionality (CINF) and from 2016 he has been director of The Villum Center for the Science of Sustainable Fuels and Chemicals (VSUSTAIN). He was elected Fellow of The Academy for Technical Sciences in 2001 and member of the Royal Danish Academy of Sciences and Letters in 2018. He has authored or coauthored more than 450 scientific papers, 23 patents and one textbook “Concepts of Modern Catalysis and Kinetics”. He has since 2017 been listed as a Highly Cited Researcher (ISI) . Ib Chorkendorff’s research activities focus on finding new catalysts for improving sustainable energy production/conversion and for environmental protection. He is co-founder of three start-up companies RENCAT APS, HPNOW APS and Spectroinlets APS and has received numerous awards, latest the Villum Kann Rassmussen Annual Award (2021), which is the most prestigious award in Denmark and in 2022 The Eni Award: Energy Frontiers Prize.