Transformation of biogenic carbohydrates into levulinic acid and further hydrogenation using supported nanoparticle catalysts synthesized by chemical fluid deposition

The primary objective of this thesis was to synthesize and identify powerful metal catalysts and key factors for the conversion of D-fructose and D-glucose to LA as well as the hydrogenation of LA to GVL. A general overview on the use of biomass for chemicals and potential biofuel production is provided. The catalytic transformation systems developed for the conversion of biomass-derived monomers to LA and GVL are reviewed. Meanwhile, an intensive overview of the preparation of supported nano-particles catalysts using chemical fluid deposition is provided. The synthesis of the supported nano-metal catalysts in a bottom up procedure using chemical fluid deposition as a universal and highly controllable production method is discussed. Here, SBA-15 is used as a mesoporous support/co-catalyst. Homo- and bimetallic Pd and/or Pt are deposited into SBA-15 by hydrogenolysis of the metal precursors (cyclopentadienyl) allyl-palladium (II) [CpPd(eta3-C3H5)] and (1, 5-cyclooctadiene)-dimethylplatinum (II) [(1,5-cod)Pt(CH3)2] with different variables and constants. The experimental catalyst synthesis plan and analysis is chosen in accordance to design of experiments (DOE, used software: Design Expert 7.1) applying response surface plans with typically seven factors. Based on a uniform design, an initially explored plan with 35 different protocols for palladium catalysts and experimental plan with 32 different protocols for nanoparticles homo- and bimetallic Pd and/or Pt are processed to investigate the influence of a variety of reaction parameters. Later, we employ the conversion of D-fructose to LA in ethanol solvent as a standard reaction to screen a wide variety of the supported homo- and bimetallic nanoparticles prepared by chemical fluid deposition method. Besides, the resulted catalysts were also used for transformation of D-glucose in combination with a salt additive. It is shown that the choice of the used solvent and metal are crucial for the product distributions. Furthermore, the stability of the resulted catalysts is also described in this chapter. The performance of the wide variety of nanoparticles catalysts was also investigated in the hydrogenation of levulinic acid to gamma-valerolactone and later to pentanoic acid which is described. Here, the maximization of GVL yields and TON optimization have been in the central focus. Furthermore, the stability and recyclability of the resulted catalysts are characterized