MgO/Carbon nanocomposites synthesized in molten salts for catalytic isomerization of glucose to fructose in aqueous media

Abstract

Isomerization of glucose into fructose has always been an important step in the biorefining process. This study synthesized a novel Mg-decorated carbonaceous catalyst by molten salt method for the application of glucose isomerization. The morphology of carbon microspheres was formed with high specific surface area and pore volume. The effects of Mg loading, catalyst dosage, reaction temperature, and reaction time were investigated and optimized. The highest fructose yield of 34.58% and fructose selectivity of 81.17% were achieved by the catalyst named Mg(100mg)/Carbon at hydrothermal temperature of 100 °C with reaction time of 1.5–2 h, showing the superiority of the catalyst. The results of recycling tests indicated Mg(100mg)/Carbon has good recyclability and can restore its activity after a simple regeneration. And the possible mechanism of glucose isomerization by Mg(100mg)/Carbon was indicated. This study provided a new method for overcoming the difficulty of high energy barrier required for glucose isomerization in the biorefining process.

Keywords

• Glucose isomerization
• Heterogeneous catalyst
• Molten salt method
• Magnesium
• Hydrothermal