From: Energetics of nanoparticle oxides: interplay between surface energy and polymorphism†
Oxide | Surface energy/J m-2 | Transformation energya/kJ mol-1 |
---|---|---|
α-Al2O3 | 2.6 ± 0.2 | 0 |
γ-A1203 | 1.7 ± 0.1 | 13.4 ± 2.0 |
A1OOH (boehmite) | 0.5 ± 0.1 | -17 ± 1 |
TiO2 (rutile) | 2.2 ± 0.2 | 0 |
TiO2 (brookite) | 1.0 ± 0.2 | 0.7 ± 0.4 |
TiO2 (anatase) | 0.4 ± 0.1 | 2.6 ± 0.4 |
ZrO2 (monoclinic) | 6.5 ± 0.2 | 0 |
ZrO2 (tetragonal) | 2.1 ± 0.05 | 9.5 ± 0.4 |
ZrO2 (amorphous) | 0.5 ± 0.05 | 34 ± 4 |
Zeolitic silicas | 0.09 ± 0.01 | 7–15 |