Catalytic conversion of biomass-derived carbohydrates into fuels and chemicals via furanic aldehydes

In recent years, substantial interest has been devoted to the conversion of biomass-derived carbohydrates into furanic aldehydes such as furfural, 5-hydroxymethylfurfural (HMF) and 5-halomethylfurfural, because these products are considered as important versatile intermediates that can be further transformed into a wide variety of high performance fuels and high value-added chemicals. However, low yields and high production costs that are due to the special chemical structures and properties of biomass-derived carbohydrates to a large extent have limited the practical production of furanic aldehydes. Recently, various catalytic conversion strategies have been developed to overcome these limitations. In this review, we systematically summarize and discuss catalytic conversion strategies from the perspective of catalysts and reaction solvents as well as formation mechanisms and influencing factors for the production of furanic aldehydes from biomass-derived carbohydrates. Meanwhile, we also outline the synthesis of furanic aldehyde-based fuels such as 2-methylfuran (MF), 2,5-dimethylfuran (DMF), 5-ethoxymethylfurfural (EMF) and alkanes and chemicals such as levulinic acid (LA), 2,5-diformylfuran (DFF) and 2,5-furandicarboxylic acid (FDCA). Moreover, some potential research orientations are proposed based on the major problems encountered in recent research.