Gel-matrix-based synthesis of porous metal oxide microstructures as catalysts in microflow reactors

• Applicants: Professor Dr. Dirk Kuckling; Professor Dr. Michael Tiemann
• Subject Area: Solid State and Surface Chemistry, Material Synthesis ; Preparatory and Physical Chemistry of Polymers
• Term: since 2025
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 569957817

This subject aims at the fabrication and testing of plug-flow microreactors (MPFR), in which various metal oxides (e.g., TiO2, Fe2O3, CuO, CoOx) are embedded as catalytically active species. The metal oxides exhibit microstructures (with periodic patterns at the sub-millimeter size scale) and pores at the nanometer scale. This concept allows an efficient flow of reactants through the catalyst, combined with a large specific surface area. In addition to the synthesis of metal oxides, noble metal nanoparticles (Pd, Pt, Au) will also be embedded in porous support materials (e.g., Al2O3, TiO2, SiO2). The microstructures will be prepared using a molding process. For this matter, microstructures of swellable hydrogels or organogels will be used as porogenic matrices (e.g., polyacrylamides, oligoethylene glycol acrylates). The latter are created by photo-induced polymerization using microstructured masks. The inorganic educts (such as metal salts or alkoxides) are infiltrated into the gels and converted there to form the metal oxides. After removal of the organic polymers (by thermal decomposition), nanopores remain in the metal oxide. This procedure has already been successfully used by the applicants. As part of the project, model microreactors with metal oxide microstructures of different sizes, shapes and geometries will be created and tested for some (photo-)catalyzed model reactions (degradation of dyes, epoxidations, Suzuki-Miyaura couplings).

• DFG Programme: Research Grants