Date of Award
Master of Science (MS)
Biomedical and Chemical Engineering
DR UV-Vis, FTIR, Hetergeneous Catalysis
Levulinic acid is a platform chemical that derived by environmental friend biomass. We have previously reported a reaction pathway to transform levulinic acid to maleic anhydride through methyl scission on supported vanadium oxide, which could achieve a 70% yield. The structure of vanadium oxide on the surface of supports can be informative for catalyst selection. We investigated the polymerization of vanadium oxide on support through diffuse reflectance UV-vis spectroscopy. Peak deconvolution of ligand to metal charge transfer region of the spectra provided knowledge of different coordinated structure. All of our catalysts have bulk V2O5 that exists on the surface of supports because of the impregnation synthesis method. Monomeric tetrahedral VOx only presents on low vanadium loading catalysts. We also examined structures of various probe molecules absorbed on the catalyst surface and difference between them as temperature increases from 313K to 693K through in situ Fourier-transform infrared spectroscopy. The binding structure of methyl ketones and levulinic acid on the catalyst was also investigated. Results confirmed our hypothesis that oxidation of levulinic acid has a distinct reaction pathway from the oxidation of methyl ketone, which is dehydration followed by dehydrogenation and oxidation instead of oxidative methyl scission.
Liu, Bowei, "Spectroscopic analysis of the vanadium oxide catalyst during the ketone oxidation" (2019). Theses - ALL. 377.