Recent advances in preparing biomass-based 2,5-bis(hydroxymethyl)furan by catalytic transfer hydrogenation

Biomass-based 2,5-bis(hydroxymethyl)furan (BHMF) is one of the important high value-added chemicals, which can be prepared from inexpensive and renewable carbohydrates through the way of catalytic conversion and selective hydrogenation, and as a widely used chemical intermediate and fuel precursor, it has unique advantages in improving the performance of traditional polyesters and synthesizing new biodegradable bio-based polyesters. In recent years, the research on the production of high value-added chemicals such as BHMF from carbohydrate has been attracting much attention from both academia and industry. However, cleanliness, high efficiency, high selectivity and low-cost remain key challenges in this area, especially for practical applications. In the process of BHMF production, the traditional hydrogenation method consumed a large amount of high-grade energy of hydrogen, and an excessive investment in infrastructure would be generated due to the security risks of higher pressure of hydrogen. On account of the advantages of catalytic transfer hydrogenation, the advances in selective hydrogenation to prepare BHMF using formic acid, alcohols and other types of hydrogen donors by the approach of catalytic transfer hydrogenation is systematically discussed in this review. In view of the features and problems of different types of hydrogen donors, catalysts and reaction processes during the catalytic transfer hydrogenation process, the effects of reaction conditions and process intensifications on the selectivity and yield of BHMF, and the merits and demerits of the reaction system were all investigated. On this basis, the future directions of new catalytic systems for preparation of BHMF by transfer hydrogenation is proposed, and the cleaner, more efficient and essential safety technologies for the production of BHMF is predicted, which will provide some scientific reference for the research and development of related catalytic systems in biomass conversion.