Structure-reactivity relationships in MoO3-based catalysts for hydrodeoxygenation of lignin pyrolysis products

• Applicants: Privatdozent Dr. Ali Abdel-Mageed, Ph.D., since 2/2022; Professorin Dr. Angelika Brückner
• Subject Area: Physical Chemistry of Solids and Surfaces, Material Characterisation ; Solid State and Surface Chemistry, Material Synthesis
• Term: since 2020
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 442613239

Renewable resources not relevant for human nutrition contain lignin as main component. They are gaining more and more importance as substitutes for fossil resources. Pyrolysis oil derived from lignin contains 20-40% of bound oxygen which must be removed before further valorization. This is done by catalytic reaction with hydrogen (hydrodeoxygenation, HDO), which in general is performed in liquid phase after condensation of the gaseous pyrolysis products. However, their HDO in the gas phase directly after leaving the pyrolysis reactor would be much more attractive, since this would make their condensation dispensable and save costs. In contrast to liquid phase HDO, there is much less research on HDO in the gas phase. Such investigations shall be performed in this project using lignin-relevant model substrates with differently bound oxygen (e. g. phenol, anisole, Guaiacol) and catalysts based on molybdenum oxide. We are following an integrated approach comprising synthesis of differently purposefully doped MoO3 catalysts, catalytic testing including optimization of reaction conditions as well as comprehensive spectroscopic in situ/operando studies to derive reaction pathways. It is the main aim of this project to elucidate if and how activity and selectivity (e. g. maintaining aromatic bonds, preventing liberation of methane) as well as stability (e. g. resistance against coke deposition) in gas phase HDO of lignin-relevant model substrates can be controlled through modification of redox and acid-base properties of MoO3 catalysts by doping with second metal ions of different valence state and reducibility.

• DFG Programme: Research Grants
• Ehemalige Antragstellerin: Dr. Angela Köckritz, until 2/2022