Green Chemicals from d-glucose: Systematic Studies on Catalytic Effects of Inorganic Salts on the Chemo-Selectivity and Yield in Aqueous Solutions

The use of inorganic salts as catalysts for the reactions of d -glucose in aqueous solutions in a batch reactor is reported. The type of salt and effect of reaction time were examined in detail at a fixed salt (5 mM) and d -glucose concentration (0.1 M) and at a temperature of 140 °C. Al(III) and Cr(II) salts gave the highest conversion of d -glucose. Typical reaction products were organic acids like lactic acid, levulinic acid, furanics like hydroxymethylfurfural and insoluble products (humins). The chemo-selectivity is a clear function of the type of inorganic salt. For Al(III), the major water soluble product was lactic acid, for Zn(II) HMF was formed in the highest yields. A reaction scheme is proposed to explain the observed product compositions.