Table 2. Amount of Surface Acidity and Acid Density of Catalysts Obtained by NH3-TPDa.
| acidity (μmol NH3 g–1 cat.) |
acid
density (μmol/m2) |
|||||||
|---|---|---|---|---|---|---|---|---|
| catalysts | weak | moderate | strong | total | weak | moderate | strong | total |
| Al2O3 | 219.6 | 556.7 | 871.3 | 1647.6 | 16.3 | 41.2 | 64.5 | 122.0 |
| HAP | 40.7 | 37.9 | 18.6 | 97.3 | 33.9 | 31.6 | 15.5 | 81.0 |
| Al50-HAP50 | 146.6 | 137.3 | 297.9 | 611.9 | 28.7 | 26.9 | 58.4 | 114.0 |
| Al20-HAP80 | 189.2 | 129.9 | 156.8 | 475.9 | 86.0 | 59.0 | 71.3 | 216.3 |
| Al20-HAP80-Pd | 312.7 | 151.4 | 105.5 | 569.6 | 100.9 | 48.8 | 34.0 | 183.7 |
a
Acid density = number of acid sites/BET surface area.