Al2O3
Alumina · Aluminum oxide, Corundum
Alumina is a chemically stable, insulating aluminum oxide widely utilized as a structural component and a versatile support material for catalysts.
About Alumina
Alumina is a thermodynamically stable oxide that serves as a cornerstone material in materials science. Its wide-band-gap electronic character makes it an exceptional electrical insulator, while its structural robustness ensures longevity in demanding chemical environments.
Because of its chemical inertness and high surface area potential, it is widely utilized as a catalyst support. It provides a stable framework for active metal phases, facilitating efficient chemical transformations across various industrial processes.
Key Properties
Cross-validated computational properties for Alumina, aggregated across 3 databases.
Band GapEnergy needed to move an electron from the valence band to the conduction band. Lower or zero values tend to behave more metallic; larger gaps are more insulating or semiconducting.
Energy Above HullThermodynamic distance from the most stable set of competing phases. 0 eV/atom is on the convex hull; small positive values may still be experimentally accessible.
StabilityA plain-language summary of the best reported energy-above-hull result. It reflects whether the lowest-energy structure is on, near, or far from the stability hull.
StructuresCount of reported calculated crystal structures for this formula, including alternate polymorphs, source databases, and observed space groups.
Reported Structures
Lowest-energy structures reported for Al2O3, ranked by energy above hull.
| Space GroupSymmetry classification of the crystal arrangement. The number is the international space-group index. | Crystal SystemBroad lattice family, such as cubic, tetragonal, monoclinic, or triclinic, derived from unit-cell symmetry. | Band Gap (eV)Electronic gap calculated for this specific reported structure, measured in electronvolts. | E above hull (eV/atom)Thermodynamic distance from the convex hull for this structure, normalized per atom. Lower is generally more stable. | E/atom (eV)Computed total energy normalized per atom. Use energy above hull, not this value alone, when comparing stability. | Density (g/cm³)Mass per relaxed crystal volume, reported in grams per cubic centimeter. |
|---|---|---|---|---|---|
| R-3c (No. 167) | trigonal | 5.85 | 0.0000 | -7.894 | 3.87 |
| C2/m (No. 12) | monoclinic | 4.46 | 0.0172 | -7.876 | 3.63 |
| Pna21 (No. 33) | orthorhombic | 4.83 | 0.0208 | -7.873 | 3.78 |
| Ia-3 (No. 206) | cubic | 5.51 | 0.0350 | -7.859 | 3.87 |
| P2/c (No. 13) | monoclinic | 4.31 | 0.0351 | -7.858 | 3.57 |
| C2/c (No. 15) | monoclinic | 4.14 | 0.0395 | -7.854 | 3.70 |
| Pbca (No. 61) | orthorhombic | 5.82 | 0.0463 | -7.847 | 4.04 |
| C2/m (No. 12) | monoclinic | 3.78 | 0.0491 | -7.844 | 3.69 |
| Cm (No. 8) | monoclinic | 3.20 | 0.0571 | -7.836 | 3.56 |
| R-3 (No. 148) | trigonal | 5.67 | 0.0747 | -7.819 | 3.81 |
| P-31c (No. 163) | trigonal | 5.49 | 0.0819 | -7.812 | 3.80 |
| C2/m (No. 12) | monoclinic | 4.21 | 0.0849 | -7.809 | 3.09 |
Synthesis Routes
Literature-extracted synthesis procedures targeting Al2O3.
Applications
Where Alumina is used.
Frequently Asked Questions
Common questions about Alumina, answered from cross-validated data.
What is Al2O3?
Alumina is a chemically stable, insulating aluminum oxide widely utilized as a structural component and a versatile support material for catalysts.
What is Al2O3 used for?
What is the band gap of Al2O3?
Is Al2O3 a metal, semiconductor, or insulator?
Is Al2O3 thermodynamically stable?
What is the crystal structure of Al2O3?
What is the density of Al2O3?
How many polymorphs of Al2O3 are known?
How is Al2O3 synthesized?
What elements does Al2O3 contain?
Where does the data for Al2O3 come from?
How It Compares
Within the spinel oxide catalysts class.
Within the family of spinel and complex oxides, Alumina stands out for its extreme thermodynamic stability and insulating nature compared to transition metal-based catalysts like CuO or NiO. While materials such as LaAlO3 share structural similarities in their oxide frameworks, Alumina is primarily valued for its role as an inert, high-performance substrate rather than for the redox-active properties found in perovskites like LaMnO3 or BiFeO3.
Related Compounds
Other Spinel Oxide Catalysts in the database.
Data sources & attribution
- materials_project — Data from the Materials Project. Cite: Jain et al., APL Materials 1, 011002 (2013).
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