XPS results of Cu/TiO2, Re/TiO2 and Cu–Re(1 : 1)/TiO2 catalysts.
| Catalyst | Cu 2p3/2 (2p1/2) (BE/eV) | Re 4f7/2 (4f5/2) (BE/eV) | |||
|---|---|---|---|---|---|
| Cu0 | Re0 | ReO2 | ReO3 | Re2O7 | |
| Cu/TiO2 | 931.7(951.6) | — | — | — | — |
| Cu–Re(1 : 1)/TiO2 | 932.0(951.9) | 40.3(43.0) | 42.0(44.2) | — | 45.8(48.2) |
| Re/TiO2 | — | — | 42.2(44.6) | 44.3(48.7) | 46.2(48.4) |