Efficient conversion of fructose to 5-hydroxymethylfurfural is a key step for using carbohydrates to produce liquid fuels and value-added chemicals. Here we show that some ionic liquids synthesized from cheap renewable materials are very efficient for the conversion of fructose to HMF. The yield and selectivity could be higher than 90% as the reaction was conducted in an ethyl acetate/renewable IL biphasic system and the separation process had no cross-contamination. Moreover, the IL can be reused easily.Diminishing fossil fuel reserves and growing concerns about global warming indicate that sustainable resources are needed in the near future. 1 Biomass is abundant, renewable, and is distributed widely in nature, which are promising alternatives for the sustainable supply of liquid fuels and valuable intermediates (such as alcohols, aldehydes, ketones, and carboxylic acids) to the chemical industry for production of drugs and polymeric materials. 2 Carbohydrates comprise the main class of biomass compounds. 3 Utilization of biomass requires efficient methods to convert carbohydrates into a variety of chemical compounds. 4 It is known that the direct production of useful organic compounds from five and six-carbon carbohydrates is difficult. 5-Hydroxymethylfurfural (HMF 2), which is obtained from carbohydrates (e.g. glucose, sucrose and fructose (1)) by dehydration, is an important "bridge" for efficient use of carbohydrates (Scheme 1). 4-6 As a versatile intermediate, HMF can be converted to 2,5-furandicarboxyl acid (3), 2,5-dihydroxy methylfuran (4), 2,5-bis(hydroxymethyl)tetrahydrofuran (5), dimethylfuran (6) and other liquid alkanes by oxidation, hydrogenation,

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ARTICLEThis journal is Catalytic transfer hydrogenation (CTH) of ethyl levulinate (EL) to γ-valerolactone (GVL) is a very attractive reaction in the field of biomass transformation. In this work, a new porous Zrcontaining catalyst with phenate group in its structure was prepared by the coprecipitation of 4hydroxybenzoic acid dipotassium salt and ZrOCl 2 (Zr-HBA) in water and characterized by powder X-Ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), N 2 adsorption-desorption, and Fourier transform infrared spectroscopy. The Zr-HBA was used as the catalyst for CTH of EL to GVL in the presence of isopropanol, and the effects of temperature, time, and amount of the catalyst on the reaction were studied. It was found that Zr-HBA was very active for the reaction and a GVL yield of 94.4% could be achieved. Meanwhile, the Zr-HBA could be reused at least five times without notable decrease in activity and selectivity. The main reason for the high catalytic activity of the Zr-HBA was that the existence of phenate in the structure of Zr-HBA increased the basicity of the catalyst, which is favourable to the CTH of EL.

Design and preparation of efficient and economical catalysts for direct hydroxylation of benzene to phenol is an important topic. In this work, a series of metal‐doped graphitic carbon nitride catalyst (Cu‐, Fe‐, V‐, Co‐, and Ni‐g‐C3N4) were successfully synthesized by using urea as the precursor through a facile and efficient method. The catalysts were characterized systematically using N2 adsorption–desorption, FTIR, thermogravimetric analysis, powder X‐ray diffraction, and X‐ray photoelectron spectroscopy techniques. It was found that the vanadium‐doped graphitic carbon nitride catalyst V‐g‐C3N4 was the most efficient catalyst for the direct synthesis of phenol from benzene with hydrogen peroxide as the oxidant and it could be recycled at least 4 times. The influence of reaction conditions such as the solvent, reaction temperature, reaction time, and the amounts of catalyst and hydrogen peroxide were investigated. Under optimized conditions, 18.2 % yield of phenol was obtained with the selectivity to phenol as high as 100 %.

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Ionic liquid 1-benzyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([BnMIm][NTf2]) can promote the generation of the ˙OOH free radical and thereby efficiently transformed the β-O-4 lignin model compound 2-phenoxyacetophenone into benzoic acid and phenol using O2 as the oxidant. Furthermore, the IL-based metal-free catalytic system can also depolymerize other lignin model compounds and organosolv lignin effectively.

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