With the shortage of fossil fuels and the concerns related to their environmental impact and greenhouse gas effect, extensive research and development programs have been initiated worldwide to convert biomass into valuable products for future biofuels and chemicals. The conversion of lignocellulose into platform chemicals has attracted more attention in recent years. During this process, cellulose and hemicellulose can be high selectively converted into soluble sugars in the presence of catalysts, and the soluble sugars are subsequently converted into widely used platform molecules, such as furan-based chemicals, polyols, organic acid and its ester derivatives. These platform molecules can be further refined into high value-added liquid hydrocarbon fuels through elementary reactions, which are important alternatives to fossil fuel. The catalysts used for the transformation of lignocellulose into various platform chemicals mainly include liquid acid, solid acid, ion liquid and multifunctional materials, which play an important role in the catalytic process. Based on the present research situation, this review provides new insights into the accomplishments in recent years in the chemocatalytic technologies to generate energy platform chemicals from lignocellulosic biomass, with an emphasis on various kinds of catalytic routes and their existing problems and possible solutions. Finally, the future research and development trend in the field is prospected.

Contents
1 Introduction
2 Conversion of lignocellulose into furan-based chemicals
2.1 5-Hydroxymethylfurfural (HMF)
2.2 Furfural
3 Conversion of lignocellulose into polyols
3.1 Hexitol
3.2 Xylitol
4 Conversion of lignocellulose into organic acid and its ester derivatives
4.1 Levulinic acid
4.2 Levulinate ester
5 Conclusion and outlook