Abstract
Certain Co/Al2O3 catalysts are active and stable for the selective catalytic reduction (SCR) of NOx by propene or propane. The addition of 30 ppm SO2 to the feed only mildly affects the catalytic performance. The effectiveness of Co/Al2O3 in the SCR process depends strongly on the Co loading, the calcination temperature, and the source of alumina. Characterization of the catalysts with UV-vis spectroscopy under ambient conditions, temperature-programmed reduction by H2 (H2-TPR), XRD, iodometric titration, and BET surface area measurements led to the proposal that there exist four different Co species: Co2+ ions in CoAl2O4, small Co3O4 particles that interact strongly with Al2O3, large Co3O4 particles, and dispersed surface Co2+ ions in octahedral coordination. The latter Co2+ species are likely the catalytically most active species. Their propensity to interact with NOx is reminiscent of that of Co ions in ZSM-5.
| Original language | English (US) |
|---|---|
| Article number | CA971869 |
| Pages (from-to) | 178-186 |
| Number of pages | 9 |
| Journal | Journal of Catalysis |
| Volume | 172 |
| Issue number | 1 |
| DOIs | |
| State | Published - 1997 |
Funding
The authors thank A. Chu-Kung and J.-H. Lee for the collection of UV-Vis spectra and Dr. B. J. Adelman for providing Co/ZSM-5. Support of this work by the U.S. Department of Energy, Basic Energy Science, General Motor Corporation, and Ford Motor Company is gratefully acknowledged.
ASJC Scopus subject areas
- Catalysis
- Physical and Theoretical Chemistry