Structural aspects of the M1 and M2 phases in MoVNbTeO propane ammoxidation catalysts
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Peter DeSanto
Abstract
The structures of M1 and M2 in MoVNbTeO propane ammoxidation catalysts have been solved using a combination of TEM, neutron powder diffraction, and synchrotron X-ray powder diffraction. The unit cell of M1 is Pba2 (No. 32) with a = 21.134(2) Å, b = 26.658(2) Å, c = 4.0146(3) Å and Z = 4. The formula unit is Mo7.8V1.2NbTe0.937O28.9. The unit cell of M2 is Pmm2 (No. 25) with a = 12.6294(6) Å, b = 7.29156(30) Å, c = 4.02010(7) Å and Z = 4. The formula unit is Mo4.31V1.36Te1.81Nb0.33O19.81. Tellurium sites in hexagonal channels of both phases are displaced toward vanadium-occupied framework sites, whereas Te in the heptagonal channel of M1 is near the channel center. The chemical topology resulting from oxidation states and Madelung site potentials presents active moieties for the ammoxidation of propane in M1 and propene in M2. EPR confirmed the presence of V4+ and possibly Mo5+ in M1 and V4+ in M2.
© 2004 Oldenbourg Wissenschaftsverlag GmbH
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- Editorial: Structure of Complex Materials – Warren Award 2003
- The atomic pair distribution function: past and present
- Local crystallography of crystals with disorder
- Obtaining structural information from the atomic pair distribution function
- PDF analysis – from atomic displacements to nanocrystals
- Synchrotron studies of lattice distortions and lattice modulations in complex oxides
- Complexity of the phase transition in La1–xSrxCoO3
- Structural aspects of the M1 and M2 phases in MoVNbTeO propane ammoxidation catalysts
- High pressure study of a Zr-based bulk metallic glass and its composite
- Spatial periodicities of defect environments in 57Fe3Al studied by Mössbauer powder diffractometry
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Articles in the same Issue
- Editorial: Structure of Complex Materials – Warren Award 2003
- The atomic pair distribution function: past and present
- Local crystallography of crystals with disorder
- Obtaining structural information from the atomic pair distribution function
- PDF analysis – from atomic displacements to nanocrystals
- Synchrotron studies of lattice distortions and lattice modulations in complex oxides
- Complexity of the phase transition in La1–xSrxCoO3
- Structural aspects of the M1 and M2 phases in MoVNbTeO propane ammoxidation catalysts
- High pressure study of a Zr-based bulk metallic glass and its composite
- Spatial periodicities of defect environments in 57Fe3Al studied by Mössbauer powder diffractometry
- Nanoporous thin films and porous inorganic substrates for lipid bilayer support materials
