Table 2.
The change in the number of acidic sites and oxygen vacancy is based on the ratio of AlO4/(AlO4 + AlO6) and ZnO6/(ZnO4 + ZnO6).
| Catalyst | Intensity Ratio of AlO4/(AlO4 + AlO6) a | Intensity Ratio of ZnO6/(ZnO4 + ZnO6) b | Acidic Sites (mmol/g) |
The Fraction of Ob (%) c |
|---|---|---|---|---|
| ZnAl2O4-550 | 0.365 | 0.409 | 0.45 | 15.7 |
| ZnAl2O4-650 | 0.222 | 0.358 | 0.32 | 13.6 |
| ZnAl2O4-750 | - | - | 0.29 | - |
| ZnAl2O4-850 | - | - | 0.1 | - |
a Intensity ratios of the AlO4 (tetrahedral site) and AlO6 (octahedral site) were obtained from the deconvolution of XPS results by using the Origin software (OriginPro 2021 9.8.0.200). b Intensity ratios of the ZnO6 (octahedral site) and ZnO4 (tetrahedral site) were obtained from the deconvolution of XPS results by using the Origin software. c The fraction of Ob was calculated via the percentage of intensity of Ob in total intensity of deconvolution O1s XPS results.