Selective methane oxidation over promoted oxide catalysts. Quarterly report, December 1994--February 1995
The objective of this research is the selective oxidative coupling of methane to C{sub 2} hydrocarbons and oxygenates, in particular formaldehyde and methanol. Air, oxygen, or carbon dioxide, rather than nitrous oxide will be utilized as the oxidizing gas at high gas hourly space velocity, but mild reaction conditions (500--700{degree}C, 1 atm total pressure). All the investigated processes are catalytic, aiming at minimizing gas phase reactions that are difficult to control. In order to optimize oxygenate space time yields over supported vanadium catalysts, testing of catalysts with various vanadium contents was carried out during this quarter. The highest oxygenate productivity from CH{sub 4}/air/steam reactants that has been observed so far was achieved with the 2.0 wt % catalyst. The effects of steam on activity and selectivity were explored in more detail over a 2 wt % V{sub 2}O{sub 5}/SiO{sub 2} catalyst prepared by impregnation of a methanol solution of vanadium(V) triisopropoxide oxide and amorphous silica. An interesting observation was that the HCHO space time yields were not significantly affected by increasing steam in the feed while those of methanol were, which indicated that the two oxygenates may be formed by separate pathways on the surface. Experiments were carried out in which the 1 wt % SO{sub 4}{sup 2{minus}}/Sr/La{sub 2}O{sub 3} and 1 wt % V{sub 2}O{sub 5}/SiO{sub 2} catalysts were physically mixed (mixed bed) instead of one lying on top of the other (double bed). With the mixed bed, the total oxygenate space time yields decreased and the HCHO space time yields dropped to virtually zero. However, the space time yields of methanol were still significant.
- Research Organization:
- Lehigh Univ., Bethlehem, PA (United States)
- Sponsoring Organization:
- USDOE, Washington, DC (United States)
- DOE Contract Number:
- FG21-92MC29228
- OSTI ID:
- 85807
- Report Number(s):
- DOE/MC/29228-4070; ON: DE95009716
- Resource Relation:
- Other Information: PBD: Mar 1995
- Country of Publication:
- United States
- Language:
- English
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