Effects of Metal Oxide Domain Size, Dispersion, and Interaction in Mixed WOx/MoOx Catalysts Supported on Al2O3 for the Partial Oxidation of Ethanol to Acetaldehyde
| Autor: | Hari Nair, and Joseph E. Gatt, Michael J. Liszka, Chelsey D. Baertsch |
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| Rok vydání: | 2008 |
| Předmět: |
Absorption spectroscopy
Chemistry Inorganic chemistry Oxide Photochemistry Surfaces Coatings and Films Electronic Optical and Magnetic Materials Catalysis Metal chemistry.chemical_compound General Energy Absorption edge Transition metal visual_art visual_art.visual_art_medium Partial oxidation Physical and Theoretical Chemistry Absorption (chemistry) |
| Zdroj: | The Journal of Physical Chemistry C. 112:1612-1620 |
| ISSN: | 1932-7455 1932-7447 |
| Popis: | UV−visible diffuse reflectance spectroscopy (UV−vis DRS) and the ethanol oxidation probe reaction were used to investigate the structure and function of binary transition metal oxide catalysts containing dispersed WOx and MoOx domains supported together on alumina. The efficacy of UV−vis DRS as a tool to identify segregated MoOx and WOx surface domains along with their growth into larger and interacting binary oxides is demonstrated for the first time. UV−vis absorption edge analysis of physical mixtures of single oxide catalysts indicates that spatially segregated domains of different composition result in multiple edges in the UV−vis absorption spectra. Binary oxide catalysts containing 0.5 Mo atoms/nm2 and 0.5 W atoms/nm2 show two distinct absorption edges at 3.60 and 4.13 eV, corresponding to spatially and compositionally segregated MoOx and WOx domains. At higher surface densities (2−8 total metal atoms/nm2) only one edge is observed, suggesting that MoOx and WOx are molecularly mixing and forming a ... |
| Databáze: | OpenAIRE |
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