aluminumoxygenhydroxyl

Aluminumoxygenhydroxyl, also called aluminum oxide hydroxide or AlO(OH), refers to a class of hydrated aluminum oxide compounds in which aluminum centers are bridged by oxide and hydroxide ligands. The minerals boehmite and diaspore are natural forms of this composition (AlO(OH)), differing mainly in crystal structure.

In these materials aluminum is typically six‑coordinate in octahedra, linked into layered or three‑dimensional networks by oxide (O2−) and hydroxide (OH−) bridges. The result is a hydrated oxide with substantial surface area and a tendency to lose water upon heating. Consequently, aluminum oxide hydroxide materials are often described as precursors to anhydrous alumina.

Occurrence and preparation: Naturally occurring as boehmite (often written γ‑AlOOH or AlO(OH)) and diaspore (α‑AlOOH or AlO(OH)); industrially produced by hydrothermal treatment of aluminum salts or by precipitation of aluminum species in basic media. Controlled dehydration converts these hydrates to forms of alumina (Al2O3), with the specific phase depending on temperature and processing.

Thermal behavior: Upon heating, aluminum oxide hydroxide dehydrates to alumina. Depending on conditions, dehydration can yield γ‑ or other polymorphs of Al2O3, which are widely used as catalyst supports and adsorbents. The high surface area of the hydrated forms contributes to their utility as precursors in various ceramic and catalytic applications.

Applications: Used as catalyst supports and adsorbents, as ceramic fillers, and as precursors to porous alumina in catalysts. They also find roles in polishing slurries and other specialty materials where high surface area and chemical versatility are advantageous.

Safety: Fine powders can pose inhalation risks; standard industrial hygiene practices apply, including appropriate ventilation and protective equipment.

See also: boehmite, diaspore, gamma-alumina.