(338e) Catalytic Non-Aqueous Processing and Hydrogenation of Chitin and Amino-Based Carbohydrates  Using Ru Carbene Organometallics Immobilized on Active Hydrotalcites

Although cellulose has garnered significant attention over the past decades in the search for renewable fuel sources that can replace petroleum fuels, chitin can be catalytically converted into similarly valuable products as well. Chitin is the second most abundant carbohydrate and only differs from cellulose by an acetyl amine on the C5 position of cellulose. In comparison to traditional mineral acids, tunable hydrotalcites (HT) promote glycosidic bond cleavage by its basic sites while dehydration of the monomer is catalyzed by its Lewis acid sites. Additionally, immobilization of homogenous catalysts onto HT create highly selective single site heterogeneous catalysts (SSHC-HT). The main challenge in the development of such a process was to pair a stable solvent that would dissolve chitin with an active heterogeneous catalyst. To overcome this challenge, a total of five systems were studied: gamma-valerolactone (GVL), GVL/levulinic acid and formic acid (as both solvent and acid), tetrahydrofuran, ionic liquids, and water. A 3:1 ratio of Mg:Al HT was used as a basis for all catalytic reactions while substitutions of Al with Fe, Cr, Ni, and Co were tested for improved catalytic activity. Hydrogenation of products were carried out using Ru and Pd HT. A wide array of products, as cited in literature under similar reaction conditions, can be generated, including 5-(hydroxymethyl)furfural, levulinic acid, amino furans, and ketones. Products were identified using LCMS, HPLC, NMR, GCMS, and FTIR.