Crab Shell-Derived Lotus Rootlike Porous Carbon for High Efficiency Isomerization of Glucose to Fructose under Mild Conditions

A crab shell waste-derived carbon/CaO composite was synthesized by a facile one-step pyrolysis strategy. The composite was used as a solid base catalyst for isomerization of biomass-derived glucose to fructose, which is a key intermediate in transformation of cellulosic biomass into chemicals and biofuels. Physicochemical structure of the composite was characterized by X-ray diffraction, Raman spectra, scanning electron microscopy, inductively coupled plasma, Brunauer–Emmett–Teller, and CO2 temperature programmed desorption. The composite showed a lotus rootlike porous structure with a surface area of 85 m2/g and contained as high as 22.4 wt % of CaO. The isomerization of glucose to produce fructose with the prepared solid base catalyst was investigated, and a maximum fructose yield of 29.2% was obtained from 5% glucose aqueous solution at mild conditions (80 °C and 40 min). A 25.0% yield of fructose still could be produced even when the initial glucose concentration was as high as 20 wt %. Finally, the m...