Table 4.
Fine structural parameters of copper species in fresh and used Cu/ZnO/Al2O3 washcoat catalysts analyzed using EXAFS spectra.
| Sample | Shell | CNa(±0.05) | Rb (±0.02 Å) | Δσ2(Å2 )c |
|---|---|---|---|---|
| Fresh Cu/ZnO/Al2O3 | Cu-O | 3.46 | 1.88 | 0.0043 |
| Cu-Cu | 3.95 | 2.69 | 0.0078 | |
| Used Cu/ZnO/Al2O3 | Cu-O | 2.86 | 1.93 | 0.0026 |
| Cu-Cu | 4.09 | 2.13 | 0.0039 | |
| Elemental Copper (Cu) | Cu-Cu | 11.05 | 2.54 | 0.0086 |
| Curous oxide (Cu2O) | Cu-O | 1.55 | 1.85 | 0.0029 |
| Cupric oxide (CuO) | Cu-O | 2.81 | 1.95 | 0.0043 |
Notes: a Coordination number; b Bond distance; c Debye-Waller factor