Abstract
We develop and validate detailed reaction mechanisms to represent the oxidative coupling of methane (OCM) over a La2O3/CeO2 nanofabric catalyst. The reaction mechanism includes 39 reversible gas-phase reactions and 52 irreversible surface reactions between 22 gas-phase species and 11 surface species. We use a model-based interpretation of spatially resolved concentration and temperature profiles measured by using a laboratory-scale packed-bed reactor. The reaction mechanisms are validated for inlet feed compositions in the range of 7≤CH4/O2≤11. The results are supported by a reaction pathway analysis that provides insight into the relative contributions of the gas-phase and surface reactions to form the desired C2+ and the undesired COx products. The results provide new quantitative insights into the complex nature of the OCM chemistry, which can assist practical process and reactor development.
| Original language | English |
|---|---|
| Pages (from-to) | 4538-4551 |
| Number of pages | 14 |
| Journal | ChemCatChem |
| Volume | 9 |
| Issue number | 24 |
| DOIs | |
| State | Published - Dec 20 2017 |
| Externally published | Yes |
Funding
R.J.K. and C.K. gratefully acknowledge support from the Air Force Office of Scientific Research (FA9550-12-1-0495) and insightful discussions with Dr. Jeffrey G. Weissman (Precision Combustion, Inc.) about OCM chemistry and processes. S.S. and B.Z. acknowledge the National Science Foundation (NSF) GRFP Support (Grant No. DGE1144087). B.Z. also acknowledges the University of California, Los Angeles (UCLA) Graduate Division Fellowship.
Keywords
- gas-phase reactions
- heterogeneous catalysts
- oxidation
- reaction mechanisms
- surface chemistry