Hydrogenation of ester levulinate to gamma-valerolactone (GVL) is an interesting reaction in biomass conversion to produce value-added chemicals. Exploration of efficient and robust catalysts is crucial for large-scale application. In this work, we conducted the reaction catalyzed by a Co catalyst, and it was found that commercially available Co₃O₄ was very efficient for this reaction under mild conditions after reduction by H₂. The effects of temperature, hydrogen pressure, amount of the catalyst used, and reaction time on the yield of GVL were studied. Under optimized conditions, the yield of GVL could reach 98%. The catalyst could be reused at least 10 times without notable loss of the activity and selectivity. The catalyst was characterized by scanning electron spectroscopy (SEM), transmission electron spectroscopy (TEM), X-ray photoelectron spectroscopy (XPS), and powder X-ray diffraction (XRD). It was demonstrated that the metallic Co⁰ was the active species for the hydrogenation reaction. As far as we know, this is the first work conducting the reaction using Co as the catalyst.

A novel method to prepare high-quality graphene is developed using simple calcination of a mixture of glucose and FeCl₃.

Efficient conversion of glucose to 5-hydroxymethylfurfural (HMF), an important platform molecular for fuels and chemicals, is a promising topic in green chemistry. In this work, several new DBU-based (DBU = 1,8-diazabicyclo[5.4.0]undec-7-ene) ionic liquids (ILs) with benzene sulfonate (BS) anion were synthesized and used as the solvents for the dehydration of glucose to HMF. It was found that all the ILs were excellent solvents for the dehydration of glucose to form HMF using CrCl₃ as the catalyst. The effects of various factors, such as kind of catalysts, catalyst amount, reaction time and reaction temperature, on the yields of HMF were studied systematically in the Et-DBUBS/CrCl₃ catalytic system. The yield of HMF from glucose could reach 83.4% under the optimized reaction conditions, and the reasons for the high yield were investigated on the basis of control experiments. The Et-DBUBS/CrCl₃ system could be reused at least five times without considerable reduction in the efficiency. Further study indicated that the catalytic system was also very efficient for transformation of fructose, inulin, and cellobiose to HMF.