Effect of titanium-doping on the properties of vanadium antimonate catalysts

A Study about the Propane Ammoxidation to Acrylonitrile with an Alumina-Supported Sb−V−O Catalyst

“…Table summarizes the XPS data. The BE value of V 2p 3/2 line (517.5 eV) is characteristic of V 5+ species in V−Sb−O-based systems, ,,,− typically above 517.0 eV. The bulk VSbO 4 phase possesses V 3+ species that must be oxidized at the outermost layer since V species in VSbO 4 possesses a very dynamic redox character. , The high value of the BE for the V 2p 3/2 line implies that all surface vanadium is in its higher oxidation state, as it has been reported for other alumina-supported Sb−V−O system .…”

“…The bulk VSbO 4 phase possesses V 3+ species that must be oxidized at the outermost layer since V species in VSbO 4 possesses a very dynamic redox character. , The high value of the BE for the V 2p 3/2 line implies that all surface vanadium is in its higher oxidation state, as it has been reported for other alumina-supported Sb−V−O system . Unsupported oxides have a different behavior, and, in addition to V 5+ , other lower oxidation states (V 4+/3+ ) can be found. ,,,,− The V 2p spectra of the fresh and used catalysts show no appreciable differences in the V 2p 3/ 2 BE (517.6 eV) or in the full width at half-maximum (fwhm) value. The stability of the oxidation state of surface vanadium after reaction was also reported by Nilsson et at …”

“…23 The BE value for Sb 3d 3/2 in the fresh catalyst is 539.8 eV. This BE value is close to that of the Sb 5+ species 16,[23][24][25][32][33][34] in V-Sb-O-based systems, but the presence of some proportion of Sb 3+ sites cannot be ruled out 16,24,25,33,34 due to the little difference in BE between both Sb oxidation states (ca. 0.8 eV).…”

“…Table 1 summarizes the XPS data. The BE value of V 2p 3/2 line (517.5 eV) is characteristic of V 5+ species in V-Sb-Obased systems, 16,23,24,[32][33][34] typically above 517.0 eV. The bulk VSbO 4 phase possesses V 3+ species that must be oxidized at the outermost layer since V species in VSbO 4 possesses a very dynamic redox character.…”

“…23 Unsupported oxides have a different behavior, and, in addition to V 5+ , other lower oxidation states (V 4+/3+ ) can be found. 13,16,23,24,[32][33][34] The V 2p spectra of the fresh and used catalysts show no appreciable differences in the V 2p 3/ 2 BE (517.6 eV) or in the full width at half-maximum (fwhm) value. The stability of the oxidation state of surface vanadium after reaction was also reported by Nilsson et at.…”

A Study about the Propane Ammoxidation to Acrylonitrile with an Alumina-Supported Sb−V−O Catalyst

“…Table summarizes the XPS data. The BE value of V 2p 3/2 line (517.5 eV) is characteristic of V 5+ species in V−Sb−O-based systems, ,,,− typically above 517.0 eV. The bulk VSbO 4 phase possesses V 3+ species that must be oxidized at the outermost layer since V species in VSbO 4 possesses a very dynamic redox character. , The high value of the BE for the V 2p 3/2 line implies that all surface vanadium is in its higher oxidation state, as it has been reported for other alumina-supported Sb−V−O system .…”

“…The bulk VSbO 4 phase possesses V 3+ species that must be oxidized at the outermost layer since V species in VSbO 4 possesses a very dynamic redox character. , The high value of the BE for the V 2p 3/2 line implies that all surface vanadium is in its higher oxidation state, as it has been reported for other alumina-supported Sb−V−O system . Unsupported oxides have a different behavior, and, in addition to V 5+ , other lower oxidation states (V 4+/3+ ) can be found. ,,,,− The V 2p spectra of the fresh and used catalysts show no appreciable differences in the V 2p 3/ 2 BE (517.6 eV) or in the full width at half-maximum (fwhm) value. The stability of the oxidation state of surface vanadium after reaction was also reported by Nilsson et at …”

“…23 The BE value for Sb 3d 3/2 in the fresh catalyst is 539.8 eV. This BE value is close to that of the Sb 5+ species 16,[23][24][25][32][33][34] in V-Sb-O-based systems, but the presence of some proportion of Sb 3+ sites cannot be ruled out 16,24,25,33,34 due to the little difference in BE between both Sb oxidation states (ca. 0.8 eV).…”

“…Table 1 summarizes the XPS data. The BE value of V 2p 3/2 line (517.5 eV) is characteristic of V 5+ species in V-Sb-Obased systems, 16,23,24,[32][33][34] typically above 517.0 eV. The bulk VSbO 4 phase possesses V 3+ species that must be oxidized at the outermost layer since V species in VSbO 4 possesses a very dynamic redox character.…”

“…23 Unsupported oxides have a different behavior, and, in addition to V 5+ , other lower oxidation states (V 4+/3+ ) can be found. 13,16,23,24,[32][33][34] The V 2p spectra of the fresh and used catalysts show no appreciable differences in the V 2p 3/ 2 BE (517.6 eV) or in the full width at half-maximum (fwhm) value. The stability of the oxidation state of surface vanadium after reaction was also reported by Nilsson et at.…”

A Study about the Propane Ammoxidation to Acrylonitrile with an Alumina-Supported Sb−V−O Catalyst

“…Table summarizes the XPS data. The BE value of V 2p 3/2 line (517.5 eV) is characteristic of V 5+ species in V−Sb−O-based systems, ,,,− typically above 517.0 eV. The bulk VSbO 4 phase possesses V 3+ species that must be oxidized at the outermost layer since V species in VSbO 4 possesses a very dynamic redox character. , The high value of the BE for the V 2p 3/2 line implies that all surface vanadium is in its higher oxidation state, as it has been reported for other alumina-supported Sb−V−O system .…”

“…The bulk VSbO 4 phase possesses V 3+ species that must be oxidized at the outermost layer since V species in VSbO 4 possesses a very dynamic redox character. , The high value of the BE for the V 2p 3/2 line implies that all surface vanadium is in its higher oxidation state, as it has been reported for other alumina-supported Sb−V−O system . Unsupported oxides have a different behavior, and, in addition to V 5+ , other lower oxidation states (V 4+/3+ ) can be found. ,,,,− The V 2p spectra of the fresh and used catalysts show no appreciable differences in the V 2p 3/ 2 BE (517.6 eV) or in the full width at half-maximum (fwhm) value. The stability of the oxidation state of surface vanadium after reaction was also reported by Nilsson et at …”

“…23 The BE value for Sb 3d 3/2 in the fresh catalyst is 539.8 eV. This BE value is close to that of the Sb 5+ species 16,[23][24][25][32][33][34] in V-Sb-O-based systems, but the presence of some proportion of Sb 3+ sites cannot be ruled out 16,24,25,33,34 due to the little difference in BE between both Sb oxidation states (ca. 0.8 eV).…”

“…Table 1 summarizes the XPS data. The BE value of V 2p 3/2 line (517.5 eV) is characteristic of V 5+ species in V-Sb-Obased systems, 16,23,24,[32][33][34] typically above 517.0 eV. The bulk VSbO 4 phase possesses V 3+ species that must be oxidized at the outermost layer since V species in VSbO 4 possesses a very dynamic redox character.…”

“…23 Unsupported oxides have a different behavior, and, in addition to V 5+ , other lower oxidation states (V 4+/3+ ) can be found. 13,16,23,24,[32][33][34] The V 2p spectra of the fresh and used catalysts show no appreciable differences in the V 2p 3/ 2 BE (517.6 eV) or in the full width at half-maximum (fwhm) value. The stability of the oxidation state of surface vanadium after reaction was also reported by Nilsson et at.…”

A Study about the Propane Ammoxidation to Acrylonitrile with an Alumina-Supported Sb−V−O Catalyst

“…Table summarizes the XPS data. The BE value of V 2p 3/2 line (517.5 eV) is characteristic of V 5+ species in V−Sb−O-based systems, ,,,− typically above 517.0 eV. The bulk VSbO 4 phase possesses V 3+ species that must be oxidized at the outermost layer since V species in VSbO 4 possesses a very dynamic redox character. , The high value of the BE for the V 2p 3/2 line implies that all surface vanadium is in its higher oxidation state, as it has been reported for other alumina-supported Sb−V−O system .…”

“…The bulk VSbO 4 phase possesses V 3+ species that must be oxidized at the outermost layer since V species in VSbO 4 possesses a very dynamic redox character. , The high value of the BE for the V 2p 3/2 line implies that all surface vanadium is in its higher oxidation state, as it has been reported for other alumina-supported Sb−V−O system . Unsupported oxides have a different behavior, and, in addition to V 5+ , other lower oxidation states (V 4+/3+ ) can be found. ,,,,− The V 2p spectra of the fresh and used catalysts show no appreciable differences in the V 2p 3/ 2 BE (517.6 eV) or in the full width at half-maximum (fwhm) value. The stability of the oxidation state of surface vanadium after reaction was also reported by Nilsson et at …”

“…23 The BE value for Sb 3d 3/2 in the fresh catalyst is 539.8 eV. This BE value is close to that of the Sb 5+ species 16,[23][24][25][32][33][34] in V-Sb-O-based systems, but the presence of some proportion of Sb 3+ sites cannot be ruled out 16,24,25,33,34 due to the little difference in BE between both Sb oxidation states (ca. 0.8 eV).…”

“…Table 1 summarizes the XPS data. The BE value of V 2p 3/2 line (517.5 eV) is characteristic of V 5+ species in V-Sb-Obased systems, 16,23,24,[32][33][34] typically above 517.0 eV. The bulk VSbO 4 phase possesses V 3+ species that must be oxidized at the outermost layer since V species in VSbO 4 possesses a very dynamic redox character.…”

“…23 Unsupported oxides have a different behavior, and, in addition to V 5+ , other lower oxidation states (V 4+/3+ ) can be found. 13,16,23,24,[32][33][34] The V 2p spectra of the fresh and used catalysts show no appreciable differences in the V 2p 3/ 2 BE (517.6 eV) or in the full width at half-maximum (fwhm) value. The stability of the oxidation state of surface vanadium after reaction was also reported by Nilsson et at.…”