Au Supported TiO_2-Nanofibers as Novel Catalysts for Glycerol Oxidation

摘要

Composites of Au supported on the TiO_2-nanofibers (Au/NF-TiO_2) were synthesized and tested in glycerol oxidation processes. TiO_2-nanofibers were prepared by a microwave-assisted hydrothermal synthesis method. Chemical deposition method was used for nanofibers modification with Au nanoparticles. Oxidation of aqueous glycerol solutions by molecular oxygen in the presence of Au/NF-TiO_2 nanocomposites was performed. It was found that Au/NF-TiO_2 composites are catalytically active in alkaline glycerol water solutions. The main product of glycerol catalytic oxidation was glyceric acid, by-products were - tartronic, lactic, glycolic, oxalic, acetic and formic acid. It was shown that Au/NF-TiO_2 catalysts' activity and selectivity depend on Au weight loading, glycerol/Au molar ratio, oxygen pressure and NaOH initial concentration. The best result was achieved usjng the 0.5 wt%Au/NF-TiO_2 catalyst: selectivity by glyceric acid was 76% with glycerol conversion 100%.