Aldose to ketose interconversion: Galactose and arabinose isomerization over heterogeneous catalysts

Isomerization of glucose, galactose and arabinose to corresponding keto-sugars was studied in the present work over a range of heterogeneous catalysts. Magnesium aluminates with different ratios between oxides resulting in materials with a Mg/Al ratio from 0.2 to 0.9 were prepared, characterized and evaluated in terms of their catalytic behavior. The catalyst with a Mg/Al ratio close to hydrotalcites was the most efficient considering activity, selectivity and stability. The sugar structure was shown to have a minor influence on catalytic activity and selectivity.