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Vanadia supported on nickel manganese oxide nanocatalysts for the catalytic oxidation of aromatic alcohols.

Adil SF, Alabbad S, Kuniyil M, Khan M, Alwarthan A, Mohri N, Tremel W, Tahir MN, Siddiqui MR - Nanoscale Res Lett (2015)

Bottom Line: It was observed that the calcination temperature and the size of particles play an important role in the catalytic process.The catalyst was evaluated for its oxidation property against aliphatic and aromatic alcohols, which was found to display selectivity towards aromatic alcohols.The samples were characterized by employing scanning electron microscopy, transmission electron microscopy, X-ray diffraction, Brunauer-Emmett-Teller analysis, thermogravimetric analysis, and X-ray photoelectron spectroscopy.

View Article: PubMed Central - PubMed

Affiliation: Department of Chemistry, College of Science, King Saud University, P.O. 2455, Riyadh, 11451 Kingdom of Saudi Arabia.

ABSTRACT
Vanadia nanoparticles supported on nickel manganese mixed oxides were synthesized by co-precipitation method. The catalytic properties of these materials were investigated for the oxidation of benzyl alcohol using molecular oxygen as oxidant. It was observed that the calcination temperature and the size of particles play an important role in the catalytic process. The catalyst was evaluated for its oxidation property against aliphatic and aromatic alcohols, which was found to display selectivity towards aromatic alcohols. The samples were characterized by employing scanning electron microscopy, transmission electron microscopy, X-ray diffraction, Brunauer-Emmett-Teller analysis, thermogravimetric analysis, and X-ray photoelectron spectroscopy.

No MeSH data available.


XPS-spectra of V2O5 (5%)-NiMnO. (a) Ni 2p spectrum. Blue: Fit for Ni 2p3/2- and 2p1/2-peak. Yellow: Fit for the two satellite peaks. Red: Envelope of both fits. (b) Mn 2p spectrum. Blue: Fit for Mn 2p3/2-peak. Yellow: Fit for Mn 2p1/2-peak. Red: Envelope of both fits. All fits were shifted to lower intensity for better visibility. (c) Spectrum over whole binding energy range. Ni, Mn, V, C, and O are marked at the highest intensity peaks. (d) Magnification of V 2p peak as marked in (c) showing the position of the 2p1/2- and 2p3/2-peak.
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Fig4: XPS-spectra of V2O5 (5%)-NiMnO. (a) Ni 2p spectrum. Blue: Fit for Ni 2p3/2- and 2p1/2-peak. Yellow: Fit for the two satellite peaks. Red: Envelope of both fits. (b) Mn 2p spectrum. Blue: Fit for Mn 2p3/2-peak. Yellow: Fit for Mn 2p1/2-peak. Red: Envelope of both fits. All fits were shifted to lower intensity for better visibility. (c) Spectrum over whole binding energy range. Ni, Mn, V, C, and O are marked at the highest intensity peaks. (d) Magnification of V 2p peak as marked in (c) showing the position of the 2p1/2- and 2p3/2-peak.

Mentions: The distinct amount of vanadium oxide supported on the surface region and the oxidation state of the vanadium were confirmed using XPS studies. The spectrum is given in Figure 4. It was also intended to establish the phase changes if any on the surface of the catalytic system before and after catalyzing the oxidation reaction. It was observed that there is no significant change in the spectrum obtained for the catalysts before and after reaction. Two weak signals observed at a binding energy (BE) of 517.0 and 522.4 eV indicate that the oxidation state of +5 for vanadium is present in the catalyst, which agree well with the results published by Silversmit et al. [39]. The very low percentage amount of vanadium could be responsible for the weak signal. The binding energies obtained for manganese and nickel (see Table 2) suggest that the oxidation states are +4 and +2, respectively [40,41], which corroborates the results obtained from the XRD. There was no change observed in the binding energies corresponding to the manganese and nickel after the reaction indicating that there is no change in oxidation state of the metals.Figure 4


Vanadia supported on nickel manganese oxide nanocatalysts for the catalytic oxidation of aromatic alcohols.

Adil SF, Alabbad S, Kuniyil M, Khan M, Alwarthan A, Mohri N, Tremel W, Tahir MN, Siddiqui MR - Nanoscale Res Lett (2015)

XPS-spectra of V2O5 (5%)-NiMnO. (a) Ni 2p spectrum. Blue: Fit for Ni 2p3/2- and 2p1/2-peak. Yellow: Fit for the two satellite peaks. Red: Envelope of both fits. (b) Mn 2p spectrum. Blue: Fit for Mn 2p3/2-peak. Yellow: Fit for Mn 2p1/2-peak. Red: Envelope of both fits. All fits were shifted to lower intensity for better visibility. (c) Spectrum over whole binding energy range. Ni, Mn, V, C, and O are marked at the highest intensity peaks. (d) Magnification of V 2p peak as marked in (c) showing the position of the 2p1/2- and 2p3/2-peak.
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Fig4: XPS-spectra of V2O5 (5%)-NiMnO. (a) Ni 2p spectrum. Blue: Fit for Ni 2p3/2- and 2p1/2-peak. Yellow: Fit for the two satellite peaks. Red: Envelope of both fits. (b) Mn 2p spectrum. Blue: Fit for Mn 2p3/2-peak. Yellow: Fit for Mn 2p1/2-peak. Red: Envelope of both fits. All fits were shifted to lower intensity for better visibility. (c) Spectrum over whole binding energy range. Ni, Mn, V, C, and O are marked at the highest intensity peaks. (d) Magnification of V 2p peak as marked in (c) showing the position of the 2p1/2- and 2p3/2-peak.
Mentions: The distinct amount of vanadium oxide supported on the surface region and the oxidation state of the vanadium were confirmed using XPS studies. The spectrum is given in Figure 4. It was also intended to establish the phase changes if any on the surface of the catalytic system before and after catalyzing the oxidation reaction. It was observed that there is no significant change in the spectrum obtained for the catalysts before and after reaction. Two weak signals observed at a binding energy (BE) of 517.0 and 522.4 eV indicate that the oxidation state of +5 for vanadium is present in the catalyst, which agree well with the results published by Silversmit et al. [39]. The very low percentage amount of vanadium could be responsible for the weak signal. The binding energies obtained for manganese and nickel (see Table 2) suggest that the oxidation states are +4 and +2, respectively [40,41], which corroborates the results obtained from the XRD. There was no change observed in the binding energies corresponding to the manganese and nickel after the reaction indicating that there is no change in oxidation state of the metals.Figure 4

Bottom Line: It was observed that the calcination temperature and the size of particles play an important role in the catalytic process.The catalyst was evaluated for its oxidation property against aliphatic and aromatic alcohols, which was found to display selectivity towards aromatic alcohols.The samples were characterized by employing scanning electron microscopy, transmission electron microscopy, X-ray diffraction, Brunauer-Emmett-Teller analysis, thermogravimetric analysis, and X-ray photoelectron spectroscopy.

View Article: PubMed Central - PubMed

Affiliation: Department of Chemistry, College of Science, King Saud University, P.O. 2455, Riyadh, 11451 Kingdom of Saudi Arabia.

ABSTRACT
Vanadia nanoparticles supported on nickel manganese mixed oxides were synthesized by co-precipitation method. The catalytic properties of these materials were investigated for the oxidation of benzyl alcohol using molecular oxygen as oxidant. It was observed that the calcination temperature and the size of particles play an important role in the catalytic process. The catalyst was evaluated for its oxidation property against aliphatic and aromatic alcohols, which was found to display selectivity towards aromatic alcohols. The samples were characterized by employing scanning electron microscopy, transmission electron microscopy, X-ray diffraction, Brunauer-Emmett-Teller analysis, thermogravimetric analysis, and X-ray photoelectron spectroscopy.

No MeSH data available.