Abstract
27Al MAS and 3QMAS NMR have been used to study Al 2O3/TiO2 catalyst supports synthesized via excess-solution impregnation and surface solgel methods. Temperature and alumina loading level strongly affect chemical states of aluminum oxide species observed. Surface cations, Al(H2O)63, a surface alumina monolayer, and disordered transitional aluminas (multilayers) and α-alumina, coexist on the TiO2 surface. Chemical shift and quadrupole coupling constants are reported for the major species identified in 3QMAS experiments. Gold particle catalysts prepared from supports calcined at 500 °C have optimum catalytic activity in CO oxidation, and smallest gold particle size for supports, which show maximum monolayer type octahedral alumina on the titania surface.
Original language | English |
---|---|
Pages (from-to) | 82-90 |
Number of pages | 9 |
Journal | Solid State Nuclear Magnetic Resonance |
Volume | 37 |
Issue number | 3-4 |
DOIs | |
State | Published - May 2010 |
Funding
Research sponsored by the Division of Chemical Sciences, Geosciences, and Biosciences, Office of Basic Energy Sciences, US Department of Energy.
Keywords
- Al MAS NMR: Al 3QMAS NMR
- Alumina-modified titania
- Aluminum speciation
- Catalyst supports
- Chemical shifts
- Quadrupole coupling constants