Abstract
Selective modification of surface and bulk V5+/V4+ ratios in Mo{single bond}V{single bond}Te{single bond}O catalysts has been achieved using nitric acid and saturated ammonia solutions as pH adjustors. The addition of nitric acid strongly suppressed V4+ in the bulk but encouraged it on the surface. Because the bulk-phase compositions of Mo{single bond}V{single bond}Te{single bond}O catalysts varied only slightly, the changes in the catalytic performance for selective propane oxidation to acrolein resulted mainly from the variation of the bulk and surface V5+/V4+ ratios. The high concentration of surface V5+ that was responsible for propane activation led to high selectivity of propylene and high conversion of propane. Increased bulk V4+ might result in oxygen vacancies, which promote the electron and oxygen transfer so as to increase the selectivity of deep oxidation products (COx). A low bulk V4+ concentration prefers selective oxidation products; the yield of acrolein was as high as 21.4%.
Original language | English (US) |
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Pages (from-to) | 382-389 |
Number of pages | 8 |
Journal | Journal of Catalysis |
Volume | 246 |
Issue number | 2 |
DOIs | |
State | Published - Mar 10 2007 |
Externally published | Yes |
Keywords
- Acrolein
- Mo{single bond}V{single bond}Te{single bond}O catalysts
- Propane
- Selective oxidation
- Surface and bulk
- V/V ratio
ASJC Scopus subject areas
- Catalysis
- Physical and Theoretical Chemistry