The Topsoe Perspective: From Electrode Nanostructures to MW Scaled SOEC Systems

Topsoe has the strategic vision of becoming global leader in carbon emission reduction technologies by 2024. This will be reached via Topsoe’s range of energy-efficient technologies to produce clean transportation fuels as well as ammonia, methanol and hydrogen, which are universally seen as the most important fuels and chemicals of the future. Topsoe develops solutions for decarbonizing hard-to-abate sectors such as steel, cement, chemicals, shipping, and aviation. For example, in 2022 Topsoe helped reduce their customers CO 2 emissions by more than 16 million tons, corresponding to 21% of the annual Danish CO 2 e emission. For decades, Topsoe has provided energy efficient solutions in the chemical industry employing heterogenous catalysis, but now Topsoe will supplement these products with Power-to-X solutions. A key technology in these Power-to-X plants will be the electrolysis system. Topsoe offers the most energy efficient electrolysis solution, namely the solid oxide electrolysis cell (SOEC) technology for its Power-to-X solutions. Topsoe’s expertise in heterogenous catalysis contributes to seamless downstream processing of products (H 2 , CO or CO+H 2 ) from the electrolysis system and ensures efficient conversion from renewable energy to valuable e-fuels. To reach the ambitious carbon emission reduction targets, an increase in electrolysis capacity is required. To enable this, Topsoe has announced the building of an SOEC manufacturing facility in Denmark. When operational in 2025, the facility will produce electrolysis stacks and modules with a capacity of 500 MW *) per year with the first agreement (a reservation of 500 MW capacity) already announced 1 . In this presentation we will provide an overview of Topsoe’s expertise, results, and initiatives in the field of SOEC. This will span from studies of materials properties, electrode nanostructures, electrochemical performance of cells and stacks, to the design of MW-sized systems, and towards commercialization of our TOPSOE SOEC electrolyzer plants as illustrated in Figure 1. The TOPSOE™ SOEC technology is applies fuel electrode supported Ni/YSZ based cells. In line with reports in literature 2–6 , we acknowledge that he SOEC technology is still not as mature as is low temperature equivalents, and as such significant R&D work is ongoing on increasing the lifetime of the cells. Recognizing the importance of high performing and durable electrodes; we will in this presentation give examples on studies of electrode nano- and microstructures applying advanced characterization techniques and illustrate the use of impedance spectroscopy for electrochemical characterization of SoA SOEC cell performance. Furthermore, stack test results applying Topsoe’s stack technology for H 2 O electrolysis will be presented. Finally, the presentation will provide a status of and outlook for Topsoe’s upscaling of SOEC production capacity. As a concluding remark, Topsoe’s TSP-2 SOEC stack technology platform for production of H 2 is being up-scaled now and ready for commercialization. Optimizing the TSP-2 platform will continue at Topsoe, by extensive R&D efforts in SOEC for the development of future even higher performing and more durable cells, stacks and modules. This is done while up-scaling and commercialization the present TSP-2 SOEC technology to provide inexpensive green H 2 to fuel the green transition already now. Figure 1 : Illustration of Topsoe’s activities in SOEC spanning from fundamental studies of electrodes; exemplified by the TEM image of fuel electrode/electrolyte interface (top); to performance measurements scaling from cells, to stacks and systems; illustrated by key numbers from the Topsoe TSP2-stack platform (bottom) References P. Blennow, T. Heiredal-Clausen, J. Rass-Hansen, J. B. Hansen; M. Hultqvist, and P.-G. Moses, in Proceedings - 14th Europrean Solid Oxide Fuel and SOE Cell Forum , p. A0304 (2022). M. B. Mogensen, M. Chen, H. L. Frandsen, C. Graves, J. B. Hansen, K. V. Hansen, A. Hauch, T. Jacobsen, S. H. Jensen, T. L. Skafte and X. Sun., Clean Energy , 3 , 175–201 (2019). M. Riedel, M. P. Heddrich, and K. A. Friedrich, Fuel Cells , 20 , 592–607 (2020). M. Trini, A. Hauch, S. De Angelis, X. Tong, P. V. Hendriksen and M. Chen, J. Power Sources , 450 , 227599-227609 (2020). Y. Shang, A. L. Smitshuysen, M. Yu, Y. Liu, X. Tong, P. S. Jørgensen, L. Rorato, J. Laurencin, and M. Chen, J. Electrochem. Soc. , submitted (2022). M. B. Mogensen, A. Hauch, X. Sun, M. Chen, Y. Tao, S. D. Ebbesen, K. V. Hansen, and P. V. Hendriksen, Fuel Cells , 17 (2017). *) Agreement between First Ammonia and Topsoe A/S announced Sept. 14 th 2022; see https://blog.topsoe.com/topsoe-and-first-ammonia Figure 1