Struktur-Reaktivitäts-Beziehungen in MoO3-basierten Katalysatoren für die Hydro-deoxygenierung von Lignin-Pyrolyseprodukten
Festkörper- und Oberflächenchemie, Materialsynthese
Zusammenfassung der Projektergebnisse
Hydrodeoxygenation (HDO) of lignin pyrolysis products is a suitable way to produce aromatics as fuel additives with a high octane number. This is currently carried out in the liquid phase under high pressure but gas-phase HDO downstream of the pyrolysis reactor, scarcely investigated so far, would be more attractive, since it would make intermediate condensation of the products obsolete and thus save costs. In this project, catalysts based on MoO3 modified with Ni, Co or Cu have been investigated in the gas-phase HDO of lignin model compounds (anisole, phenol, guaiacol) in comparison to liquid-phase HDO, with the aim to clarify whether and how activity, selectivity and stability depend on structural properties of the catalysts. Pure MoO3 showed moderate performance (Xanisole<40%) with an induction period of several hours during which an active MoOxCyHz was formed, followed by slow deactivation by carbon deposits. This phase accumulated during repeated cycles of HDO and oxidative regeneration, leading finally to Xanisole≈100%. Introduction of Ni or Cu improved activity (Xanisole ≈100%) and selectivity to aromatics markedly, whereby the best performance without any induction period was obtained with the pure metal molybdate phases MMoO4 (M=Ni,Cu). Due to its enhanced reduction and hydrogen dissociation ability, Ni promotes the formation of the MoOxCyHz phase but catalyzes, too, the undesired hydrogenolysis of the aromatics to form methane. This is not the case for CuMoO4, which prevents deep reduction of the surface, making it a superior catalyst compared to NiMoO4. MoO3, the Ni containing molybdate catalysts as well as CoMoO4 have also been tested in liquid-phase HDO of anisole, phenol and guaiacol to explore, whether they could be a cheaper alternative for the currently used noble metal catalysts based on rhenium. The results demonstrated that MoO3-based catalysts cannot compete with rheniumbased state-of-the-art catalysts. In particular, they are unsuitable for liquid-phase HDO with guaiacol. The main products in this case were oxygenates such as phenol and anisole. This may be due to the Brønsted acidity of the catalysts.
Projektbezogene Publikationen (Auswahl)
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Gas-Phase Hydrodeoxygenation of Anisole on Metal Molybdate Catalysts, Catalysis: Fundamentals and Practice Summer School, Liverpool, 18.-22.07. 2022 (Poster).
S. Haida, S. Löbner, C. Kubis, H. Lund, A. M. Abdel-Mageed & A. Bückner
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Investigations of Molybdenum Based Catalysts for the Gas-Phase Hydrodeoxygenation of Anisole, 55. Jahrestreffen Deutscher Katalytiker, Weimar, 27.-29.06. 2022 (Poster).
S. Haida, S. Löbner, C. Kubis, H. Lund, A. M. Abdel-Mageed & A. Bückner
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Structural Changes of Metal Molybdate Catalysts in Gas-Phase Hydrodeoxygenation, 6th RoHan DAAD SDG Winter School, Hanoi (Vietnam), 7.-10.11.2022 (Vortrag).
S. Haida, S. Löbner, H. Lund, A. M. Abdel-Mageed, C. Kubis & A. Brückner
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Investigation of metal molybdate catalysts for the hydrodeoxygenation of anisole, Europacat XV, Prag, 27.8.-1.9.2023 (Poster).
S. Löbner, S. Haida, C. Kubis, H. Lund, A. Brückner & A. M. Abdel-Mageed
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MoOxCyH Phases in Metal Molybdate Catalysts for Gas Phase Hydrodeoxygenation, Operando VII, Grindelwald, Switzerland, 07- 11.05.2023 (Poster).
S. Haida, S. Löbner, C. Kubis, H. Lund, A. M. Abdel-Mageed & A. Bückner
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On the Role of Nickel in Doped MoO3 Based Catalysts, Europacat XV, Prag, 27.08.-01.09.2023 (Poster).
S. Haida, S. Löbner, H. Lund, A. Abdel-Mageed, S. Wohlrab, N. Escalona, C. Kubis & A. Brückner
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Promotion of MoOxCyHz Phase Formation by Nickel in Molybdenum Catalysts, 56. Jahrestreffen Deutscher Katalytiker, Weimar, 15.- 17.03. 2023 (Poster).
S. Haida, S. Löbner, C. Kubis, H. Lund, A. M. Abdel-Mageed & A. Bückner
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Enhanced Anisole Hydrodeoxygenation by Nickel Improved MoOxCyHz Phase Formation, 57. Jahrestreffen Deutscher Katalytiker, Weimar, 13.–15.03.2024 (Poster).
S. Haida, S. Löbner, H. Lund, A. M. Abdel-Mageed, C. Kubis & A. Brückner
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Insights from Kinetic Investigations of the Gas- Phase Hydrodeoxygenation of anisole on MoOx-based catalysts, 18th International Congress on Catalysis (ICC), Lyon, Frankreich, 14.-19.07.2024 (Poster).
S. Löbner, S. Wohlrab, A. M. Abdel-Mageed & S. Bartling
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Investigations into the influence of nickel loading on MoO3-modified catalysts for the gas-phase hydrodeoxygenation of anisole. Catalysis Science & Technology, 14(8), 2201-2217.
Haida, Simon; Löbner, Sebastian; Lund, Henrik; Bartling, Stephan; Kreyenschulte, Carsten; Atia, Hanan; Abdel-Mageed, Ali M.; Kubis, Christoph & Brückner, Angelika
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Structure-Reactivity Relationships of MoO3-Based Catalysts for the Hydrodeoxygenation of Lignin Pyrolysis Products, PhD Thesis, University of Rostock, 11. 10. 2024.
S. Haida
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Activity, selectivity and regeneration of copper molybdate as a catalyst for the hydrodeoxygenation under flow conditions. Applied Surface Science, 732, 166383.
Löbner, Sebastian; Wolicki, Rafal Damian; Haida, Simon; Kubis, Christoph; Lund, Henrik; Bartling, Stephan; Atia, Hanan; Giacomo, Stefano Di; Profio, Pietro Di; Wohlrab, Sebastian; Brücker, Angelika & Abdel-Mageed, Ali M.
