Abstract
The molecular structure and catalytic performance of (MoOx)n/TiO2, (WOx)n/TiO2 and (VOx)n/TiO2 catalysts (synthesized by the equilibrium–deposition–filtration/EDF method) for oxidative dehydrogenation (ODH) of ethane were studied by in situ Raman spectroscopy at 430 °C and catalytic measurements in the temperature range of 420–480 °C. The extent of association within the deposited oxometallic phase followed the sequence (VOx)n/TiO2 >> (MoOx)n/TiO2 > (WOx)n/TiO2; a concurrent trend in reduction susceptibility was evidenced by exploiting the relative normalized Raman band intensities while monitoring the response of the vibrational properties of the catalytic samples under reactive (C2H6/O2/He) and reducing (C2H6/He) conditions by in situ Raman spectroscopy. The catalyst reactivity tracks the corresponding trend in reduction susceptibility as evidenced by the in situ Raman spectra. Selective reaction pathways are favored at high coverage whilst combustion routes are activated at low coverages due to the involvement of carrier lattice oxygen sites. The observed apparent reaction rates and activation energies are discussed in relation to various structural and reactivity aspects.
Original language | English (US) |
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Pages (from-to) | 1226-1236 |
Number of pages | 11 |
Journal | Comptes Rendus Chimie |
Volume | 19 |
Issue number | 10 |
DOIs | |
State | Published - Oct 1 2016 |
All Science Journal Classification (ASJC) codes
- General Chemistry
- General Chemical Engineering
Keywords
- Equilibrium deposition filtration
- In situ Raman spectroscopy
- Molybdenum oxide
- ODH of ethane
- Titania-supported catalysts
- Tungsten oxide
- Vanadium oxide