Catalytic transfer hydrogenation of biomass-derived 5-hydroxymethylfurfural into 2,5-dihydroxymethylfuran over magnetic zirconium-based coordination polymer

Catalytic transfer hydrogenation (CTH) of 5-hydroxymethylfurfural (HMF) into 2,5-dihydroxymethylfuran (DHMF) via Meerwein-Ponndorf-Verley (MPV) reaction is a very important pathway for the effective utilization of biomass. In this process, the development of high-efficiency heterogeneous catalysts is the key, which has attracted increasing attention in recent years. Herein, a zirconium-based organic-inorganic coordination polymer with magnetic property (MZCCP) was successfully prepared by the reaction of zirconium tetrachloride (ZrCl4) and cyanuric acid (CA) on the surface of ferriferrous oxide (Fe3O4). As expected, MZCCP was an excellent acid-base bifunctional catalyst with the higher acid-base strength and content and the proper acid-base ratio as well as the appropriate surface area and pore size, and so it showed high catalytic activity for the CTH of HMF into DHMF with satisfactory yield of 93.4% at a moderate reaction temperature of 140 degrees C for 5 h in the presence of 2-butanol, which simultaneously acted as hydrogen donor and reaction medium. Furthermore, it should be specially noted that MZCCP could be easily separated from the reaction mixture by using an outer magnet, and repetitively used at least five reaction runs without an obvious loss of activity. More importantly, MZCCP could also be applicable for the CTH of 5-methylfurfural (MF), furfural (FF), cyclohexanone (CHN), levulinic acid (LA) and ethyl levulinate (EL) into the corresponding products in high yields, indicating that it possessed a superior universality for the selective reduction of various biomass-derived carbonyl compounds.