Catalytic isomerization of D-glucose to D-fructose over BEA base zeotypes using different energy supply methods

The isomerization of D-glucose (Glu) to D-fructose (Fru) is a key step in the selective conversion of carbohydrate biomass to renewable products and has long been of great importance in the food and beverage industry. Expansion of the Fru market (food, non-food) poses various challenges to enhance productivity, where energy efficiency and use of cheap, robust synthetic catalysts may play important roles. Here, Glu isomerization, using water as the sole solvent, was studied using (i) micro/mesoporous catalysts of different compositions prepared from commercial zeolite Beta, and (ii) different energy supply methods, namely conventional conductive heating, microwave irradiation and ultrasound waves, at 75 °C. The type of energy supply method influenced the initial turnover frequency. Besides catalytic activity, the stability is important, which depended on the catalytic material properties (e.g., composition, textural properties), type of energy supply method and reaction temperature. Favourable results were verified for Glu isomerization using a hierarchical potassium/magnesium-containing Beta catalyst and ultrasound waves, at 75 °C.