Selective Transformation of Biomass through Dehydration and Reduction

In this introduction, a general overview of the role of biomass as an alternative source of chemicals and fuels will be given. In particular, the contribution of the cluster of excellence “Tailor Made Fuel from Biomass (TMFB)” will be briefly described. Levulinic acid (LA) has been identified by the cluster as an important intermediate for the production of biofuels. Thus, after pointing out the importance of LA, an extensive overview as well as a general assessment of the existing processes for its production from biomass feedstock will be provided. The focus lies on the applied homogeneous and heterogeneous catalysts for this transformation. Specifically, sulfonated graphene oxide (GO) seemed as a potential highly active catalyst. Therefore, an overview of the synthesis methods and the physical and chemical properties of this kind of catalysts will be given. Subsequently, the further conversion of LA to a potential biofuel, γ-valerolactone (GVL), will be introduced. Here, a summary of the state of the art of supported metal catalysts applied in this transformation as well as the limitations related to their use will be provided. In this thesis, supported Pt and Pd nanocatalysts were applied for the hydrogenation of LA. Therefore, the importance of these precious metals in catalysis will be first summarized. Second, a general overview of the synthesis methods of supported nanoparticles in liquid and gas phases and their limitations will be provided. Finally, an alternative synthesis method using supercritical fluids, the so-called “Chemical Fluid Deposition (CFD)” will be introduced. At the end of this chapter, the thesis structure will be given