Table 1. Textural Properties of Mg(OH)2 Modified with x % F (by wt) That Was Calcined at 400 and 500 °C for 3 h in Air and the Crystallite Size of the Obtained Phases, as Calculated from XRD Patterns.
| XRD
crystallite size (nm)a |
||||||||
|---|---|---|---|---|---|---|---|---|
| adsorbent composition | MgO* cubic | MF2** tetragonal | SBET(m2/g) | external surface area (m2/g) | micropore area (m2/g) | total pore volume (cm3/g) | mesopore volume (cm3/g) | average pore diameter (nm) |
| Mg(OH)2 + 20% F-400 | 9.4 | 3.2 | 153.22 | 145.79 | 7.43 | 0.23 | 0.23 | 3.7 |
| Mg(OH)2 + 30% F-400 | 7.9 | 8.9 | 117.18 | 111.49 | 5.68 | 0.26 | 0.26 | 3.7, 13.0 |
| Mg(OH)2 + 40% F-400 | 8.6 | 14.6 | 88.27 | 79.39 | 8.88 | 0.29 | 0.29 | 3.6, 16.0 |
| Mg(OH)2 + 50% F-400 | 19.1 | 72.22 | 61.59 | 10.62 | 0.31 | 0.30 | 3.6, 18.9 | |
| Mg(OH)2 + 20% F-500 | 12.0 | 22.7 | 103.06 | 96.25 | 6.81 | 0.24 | 0.24 | 3.5, 6.1 |
| Mg(OH)2 + 30% F-500 | 8.6 | 22.8 | 81.93 | 80.74 | 1.18 | 0.16 | 0.16 | 3.6 |
| Mg(OH)2 + 40% F-500 | 9.9 | 21.6 | 58.32 | 54.31 | 4.00 | 0.13 | 0.13 | 3.7, 33.0 |
| Mg(OH)2 + 50% F-500 | 26.7 | 39.70 | 33.83 | 5.87 | 0.12 | 0.11 | 3.5, 33.8 | |
a
The position of the most intense peak is at (*) 2θ = 42.84° (200) in the case of MgO and (**) = 40.38° (111) in the case of MgF2.