The oxidation of 5-hydroxymethylfurfural (HMF) to 2,5-furandicarboxylic acid (FDCA) is highly attractive as FDCA is considered as substitute for the petrochemically derived terephthalic acid. There are only few reports on the direct use of unrefined HMF solutions from biomass resources and the influence of remaining constituents on the catalytic processes. In this work, the oxidation of HMF in a solution as obtained from hydrolysis and dehydration of saccharides in chicory roots was investigated without intermediate purification steps. The amount of base added to the solution was critical to increase the FDCA yield. Catalyst deactivation occurred and was attributed to poisoning by amino acids from the bio-source. A strong influence of amino acids on the catalytic activity was found for all supported Au, Pt, Pd, and Ru catalysts. A supported AuPd(2 : 1)/C alloy catalyst exhibited both superior catalytic activity and higher stability against deactivation by the critical amino acids.

The phase width of the copper hydroxycarbonate malachite, Cu 2 CO 3 (OH) 2 , upon substitution with magnesium has been studied in detail. In extension of a previous study on amorphous precursors, the introduction of a hydrothermal aging step allowed the retrieval of crystalline hydroxycarbonate samples with up to 37 atom % Mg (metal content) that are suitable candidates as precursors to Cu/MgO catalysts for CO hydrogenation. Simultaneous refinements of X-ray powder diffraction and pair distribution function (PDF) data as well as complementary spectroscopic insight (X-ray absorption and infrared spectroscopy) revealed that samples with up to 18 atom % Mg are phase-pure magnesian malachites but the magnesium content can be increased beyond this threshold when mcguinnessite (CuMgCO 3 (OH) 2 ) is accepted as a side phase. In a complementary study, a continuous increase of the magnesium fraction was found during aging and the corresponding structural evolution was studied by means of PDF. These findings add significant insight into the aging chemistry of crystalline Cu,Mg hydroxycarbonates. Furthermore, both phase-pure magnesian malachite and mcguinnessite-containing samples with up to 37 atom % Mg have been examined by thermogravimetry, X-ray powder diffraction, and N 2 physisorption and were found to be promising candidates for use as precursors for the preparation of Cu/MgO catalysts.