7704-99-6

Gray-black metallic powder. Stable toward air and water.

Zirconium hydride is a powerful reducing agent in acid solution or at high temperatures; hydrogenation catalyst; in the vacuum tube industry.Also, it is used as a source of pure hydrogen and a catalyst in hydrogenation reactions. Some other applications are in powder metallurgy; as a moderator in nuclear reactors; and as a metal-foaming agent

Flammable, dangerous fire risk, especially in the presence of oxidizers.

Grayish-black powder; density 5.60 g/cm³; stable in water; soluble in dilute hydrofluoric acid; soluble in concentrated acids.

Zirconium hydride may be prepared by heating zirconium oxide with magnesium in the presence of hydrogen: ZrO₂ + 2Mg + H₂ → ZrH₂ + 2MgO
Alternatively, hydride may be made by heating zirconium oxide with calcium hydride in the presence of hydrogen
Hydride also may be obtained by combining zirconium metal with hydrogen at elevated temperature.

Zirconium hydride in powder form was produced by the reduction of zirconium oxide with calcium hydride in a bomb reactor. However, the workup was hazardous and many fires and explosions occurred when the calcium oxide was dissolved with hydrochloric acid to recover the hydride powder. With the ready availability of zirconium metal via the Kroll process, zirconium hydride can be obtained by exothermic absorption of hydrogen by pure zirconium, usually highly porous sponge. The heat of formation is 167.4 J/mol (40 kcal/mol) hydrogen absorbed.

Flammable