The development of green and renewable energy sources is one of the crucial and effective approaches to mitigating carbon footprint from fossil fuels. Biomass-derived furanyl diethers, including a library of...

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2,5-Bis(hydroxymethyl)furan (BHMF) as well as furfuryl alcohol (FFA) are considered as highly valuable biomass-derived alcohols resembling aromatic monomers in polymer synthesis. Herein, a series of cobaltic nitrogen-doped carbon (CoÀ NC) catalysts calcinated at different temperatures were synthesized and tested for the solvent-free hydrogenation of 5hydroxymethylfurfural (HMF) to prepare BHMF. It was found that the CoÀ NC catalyst calcinated at 600 °C (CoÀ NC-600) exhibited a superior catalytic activity in the hydrogenation reaction mainly due to the doping of graphitic N, which probably facilitated the polarization of H 2 to afford H + and H À .Consequently, CoÀ NC-600 offered a high BHMF/FFA yield greater than 90 % with a nearly complete conversion of HMF/ furfural (FF) at the optimal conditions (80 °C, 4 h, and 5 MPa H 2 ). After the hydrogenation reaction, CoÀ NC catalyst was facilely recycled by magnetic separation, and the obtained BHMF/FFA was then successfully transformed into hypercrosslinked polymers with an excellent CO 2 /H 2 storage capacity comparable to aromatic hydroxymethyl polymers. Therefore, this is a novel and facile two-step pathway for the conversion of biomass-derived HMF/FF towards functional polymers from both industrial and environmental perspectives.

Direct production of biomass-derived 2,5-bis(hydroxymethyl)furan (BHMF) from raw hexoses, especially glucose, is extremely desirable but challenging owing to the multistep reactions composed of isomerization, dehydration, and hydrogenation as well as inevitable side reactions to form humins involved. In this context, we developed a highly selective, energy-saving, and environmentally friendly approach to producing BHMF through the cyclic conversion of glucose in a water/ethyl acetate (EtAc) biphasic medium, in which ZIF-67, H2SO4, and CoNC-600 are used for catalyzing isomerization, dehydration, and hydrogenation, respectively. Under the optimized conditions, ∼40% glucose was converted to form BHMF with a desired carbon balance greater than 92% in the single cycle, where the unconverted glucose solution can be reacted in the next cycle. After the reaction, EtAc can be easily recycled by vacuum distillation at a low temperature and simultaneously afford solid BHMF with a purity of ∼90%. Moreover, s-CoNC-600 prepared from the spent ZIF-67 was still highly active and stable for the hydrogenation of HMF into BHMF. This work proposed an integrated and promising strategy for improving the selectivity of BHMF using low-cost glucose as the substrate, showing a great referential value for the industrial utilization of lignocellulosic biomass resources.