Direct conversion of carbohydrates to diol by the combination of niobic acid and a hydrophobic ruthenium catalyst

Tetrahydro-2,5-furandimethanol (THFDM) was obtained directly from a wide variety of carbohydrates by the combination of niobic acid and a hydrophobic ruthenium catalyst. Fructose, glucose, and polysaccharides consisting of fructose or glucose could be converted to THFDM in one-step. The selectivity to THFDM was kept around 60% while the glucose conversion varied from 9% to 49%. The as-synthesized niobic acid was characterized by TEM, N2 adsorption/desorption, XRD, NH3-TPD and FT-IR spectra of adsorpted pyridine. The niobic acid was proved to have medium and strong acid sites with a high Brönsted/Lewis ratio, which played a great role for keeping high THFDM selectivity using glucose as a substrate.