Selective methane oxidation over promoted oxide catalysts. Quarterly report, December 1993--February 1994
A great deal of experimental research was carried out in previous quarters with sulfate-doped Sr/La{sub 2}O{sub 3} catalysts that are very active for the oxidative coupling of methane. Data analysis has been continued, and the results are discussed further in this quarterly report. In addition to data analysis, a new postdoctoral research scientist has been employed this quarter to work on this research project, particularly in terms of developing catalysts and processes for switching the product selectivity away from C{sub 2} hydrocarbons and to oxygenates. Analysis of the catalytic testing data demonstrates that the 1 wt% SO{sub 4}{sup 2{minus}}/1 wt% Sr/La{sub 2}O{sub 3} catalyst is stable at reaction temperatures below 600{degrees}C. Even after extensive testing in which reaction parameters such as gas hourly space velocity and temperature were systematically varied, the catalyst exhibited reproducible activity in terms of CH{sub 4} conversion and selectivity to C{sub 2} hydrocarbons. It is shown that the La{sub 2}O{sub 3}, Sr/La{sub 2}O{sub 3}, and SO{sub 4}{sup 2{minus}}/Sr/La{sub 2}O{sub 3} catalysts exhibit the same correlation between CH{sub 4} conversion and C{sub 2} hydrocarbon selectivity (i.e. as CH{sub 4} conversion increases, the C{sub 2} hydrocarbon selectivity increases) and in ethene/ethane selectivities ({approx}1/1, especially at higher conversions). This indicates that the mechanism for activating methane on the catalysts is probably the same for all the catalysts. The high C{sub 2} selectivity at high CH{sub 4} conversion appears to be due to the depletion of oxygen at high conversions, and this enhances the driving force toward partial oxidation products. At the same time, the lower levels of CO{sub 2} produced decrease the poisoning effect of carbonate formation on the catalyst.
- Research Organization:
- Lehigh Univ., Bethlehem, PA (United States)
- Sponsoring Organization:
- USDOE, Washington, DC (United States)
- DOE Contract Number:
- FG21-92MC29228
- OSTI ID:
- 10160924
- Report Number(s):
- DOE/MC/29228-3770; ON: DE94004135; TRN: 94:006575
- Resource Relation:
- Other Information: PBD: Apr 1994
- Country of Publication:
- United States
- Language:
- English
Similar Records
Selective methane oxidation over promoted oxide catalysts. Quarterly report, December 1994--February 1995
Selective methane oxidation over promoted oxide catalysts. Quarterly report, March--May 1994