Chemo-catalytic synthesis of biomass-derived furanyl diethers: green and renewable bio-diesel components

Abstract

The development of green and renewable energy sources is one of the crucial and effective approaches to mitigate the carbon footprint from fossil fuels. Biomass-derived furanyl diethers, including a library of C8–C14 2,5-bis(alkoxymethyl)furans, are regarded as sustainable bio-fuel additives that have great potential for improving the combustion performance of commercial diesels owing to their superior physicochemical properties, e.g., high energy density and cetane number. In recent years, furanyl diethers have drawn more attention from researchers and several obvious breakthroughs were achieved. However, selective and efficient synthesis of furanyl diethers from biomass-derived sugars or cellulose is challenging as a result of various side reactions under the conditions of acid-catalyzed hydrolysis and etherification. Across the growing body of literature in this field, this article collected and compared the engine performance parameters of various furanyl diethers and systematically summarized their mechanistic pathways and preparation methods, and emphatically discussed the adjustment and cooperative actions of Lewis and Brønsted acid sites of catalysts as well as the influence of alcoholic solvents on the electron transfer and the supply of hydrogen. Moreover, based on the problems and regularities in these studies, we proposed a number of feasible research directions and strategies for paving the way to the industrial production and application of furanyl diethers.