Improvement of furanic diether selectivity by adjusting Bronsted and Lewis acidity

Furanic diethers are considered as one of potential biofuels or green solvents. 2,5-Bis(methoxymethyl)furan (BMMF), diether of 2,5-bis(hydroxymethyl)furan (BHMF) with methanol, is difficult to effectively synthesize in traditional homogeneous catalytic systems due to active groups of BHMF. In this case, HCl and AlCl3, representatives of Bronsted and Lewis acid, are separately employed to explore catalytic performance in BHMF etherification. We also demonstrated that Lewis and Bronsted acid not only synergistically catalyze the etherification but also take respectively charge of main and side reactions. Subsequently, the catalytic performance of ZSM-5 and modified ZSM-5 proved this conclusion. High yield and selectivity of BMMF catalyzed by 1.5%Sn-ZSM-5 was obtained, about 95%, which may be attributed to suitable Bronsted and Lewis acidity as well as pore structure. This suggests that synthesis of BMMF by using solid acid is possible in the future industrialization