| Catalyst | peak position of Mg 2p (eV) | Mg/(Mg + Ce) ratio on surface (%) |
| Au/Mg(OH)2-CeO2 (6.5%) | 49.44 | 5.76 |
| Au/Mg(OH)2-CeO2 (20%) | 49.46 | 11.55 |
| Au/Mg(OH)2-CeO2 (37.5%) | 49.55 | 63.53 |
| Au/Mg(OH)2-CeO2 (50%) | 49.29 | 76.10 |
| Au/Mg(OH)2 | 48.91 | 100 |