Alumina Catalyst Support

Alumina (Al₂O₃) catalyst supports are indispensable in industrial catalysis, accounting for approximately 70% of all supported catalysts. Their versatility stems from a unique combination of physical, chemical, and structural properties that enable efficient dispersion of active metal species, resistance to harsh conditions, and tunability for diverse applications.

Alumina Catalyst Support Structural Features

Morphological Diversity:

Forms: Available as powders or pre-shaped solids (e.g., spheres, pellets, honeycombs) for fixed-bed or fluidized-bed reactors.

Crystal Phases: Transition aluminas (e.g., γ-, η-, θ-Al₂O₃) dominate catalysis due to their high surface areas (10–100 m²/g), while α-Al₂O₃ is used for thermal stability.

Porosity: Macroporous structures (0.45–0.7 g/cm³ bulk density) facilitate mass transfer, with pore volumes ≥0.45 mL/g and tunable distributions.

Surface Chemistry:

Acidity: Lewis and Brønsted acid sites enable bifunctional catalysis (e.g., Pt/Al₂O₃ in reforming).

Hydroxyl Groups: Critical for anchoring metal precursors during impregnation.

Thermal/Chemical Stability:

Withstands temperatures >1000°C (α-Al₂O₃) and resists sintering, making it ideal for high-temperature reactions (e.g., automotive exhaust conversion).

Chemically inert under mild conditions but may interact with strong acids/bases.