Catalytic conversion of glucose into alkanediols over nickel-based catalysts: a mechanism study

摘要

The conversion of isotope-labeled glucose (D-1-C-13-glucose) into alkanediols was carried out in a batch reactor over a Ni-MgO-ZnO catalyst to reveal the C-C cleavage mechanisms. The unique role of the MgO-ZnO support was highlighted by C-13 NMR and GC-MS analysis qualitatively and the MgO-ZnO favored isomerization of glucose to fructose. C-13 NMR, GC-MS and HPLC analysis demonstrated that the Cl position of ethylene glycol, the Cl and C3 positions of 1,2-propanedioE and the Cl position of glycerin were labeled with C-13, which is attributed to a C-C cleavage at D-1-C-13-glucose's corresponding positions through retro-a[doE condensation. A hydrogenoEysis followed by hydrogenation pathway was proposed for glucose converted into alkanediols at 493 K with 6.0 MPa of H2 pressure over Ni based catalysts.