Synthesis, characterization, and activity studies of vanadia supported on zirconia and phosphorus-modified zirconia
- Univ. of Guelph, Ontario (Canada). Dept. of Chemistry and Biochemistry
A series of catalysts with vanadia contents varying between 1 and 14 wt % were prepared by the wet impregnation technique on zirconia and phosphorus-modified zirconia. The catalysts were characterized by employing X-ray diffraction (XRD), electron spin resonance (ESR) spectroscopy, {sup 51}V, {sup 31}P, and {sup 1}H solid-state magic angle spinning nuclear magnetic resonance (MAS NMR), Fourier transform Raman spectroscopy (FT-Raman), diffuse reflectance Fourier transform infrared spectroscopy (DRIFTS), and Brunauer-Emmett-Teller (BET) surface area measurements. The activities of the catalysts were determined by an ethanol partial oxidation reaction. {sup 51}V solid-state NMR studies of both series of catalysts indicated the presence of tetrahedral vanadate species at lower loadings, and octahedrally coordinated vanadium species at higher concentrations. DRIFTS studies of the catalysts were in conformity with NMR studies as the vibrations corresponding to tetrahedral vanadate species were observed at low V{sub 2}O{sub 5} loadings and at higher vanadia contents the vibrations corresponding to polymeric decavanadate species were seen. All of the XRD, ESR, {sup 51}V solid-state NMR, FT-Raman, and DRIFTS results indicated weaker interaction of vanadia with zirconia support upon phosphate modification. Activity studies were in agreement with spectroscopic data, as reflected in higher ethanol partial oxidation activities of the V{sub 2}O{sub 5}/ZrO{sub 2} catalysts.
- OSTI ID:
- 352684
- Journal Information:
- Langmuir, Journal Name: Langmuir Journal Issue: 10 Vol. 15; ISSN LANGD5; ISSN 0743-7463
- Country of Publication:
- United States
- Language:
- English
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