Catalytic Hydrogenation of 5-Hydroxymethylfurfural to Hexanetriol

The catalytic conversion of furan derivatives, furfural and 5-hydroxymethylfurfural (HMF), to valuable chemicals is of great importance due to the increase in carbon emissions and decrease in fossil fuels. In this manuscript, 1,2,5-hexanetriol was transformed to HMF through a two steps procedure. The HMF was first hydrogenated to 1-hydroxyhexane-2,5-dione (HHD). The reaction scale could be enlarged from 1 mmol to 50 mmol of the reactant with a similar yield of HHD, and the purity of HHD was over 95 % after a simple extraction. Then the HHD was hydrogenated to 1,2,5-hexanetriol on Ru/C at very mild reaction conditions. The parameters of pressure, solvent, the concentration of HHD, reaction time and temperature on the hydrogenation of HHD were investigated to find the optimal reaction conditions. The 1,2,5-hexanetriol could be obtained from HMF in a one-pot reaction by removing the Pd/C and adding Ru/C after the HMF hydrogenation step. The fresh and used Pd/C and Ru/C were characterized by XRD, TEM, XPS, and the Ru/C was further characterized by EDS mappings. The characterization showed partial agglomeration of Pd occurred after the Pd/C was used. The Ru/C had a narrow Ru distribution and was stable under the reaction conditions. The Ru/C could be used at least 5 times. This manuscript showed an easy route for the production of valuable chemicals from renewable biomass furan derives.