Zirconiumdihydrid Chemische Eigenschaften,Einsatz,Produktion Methoden
R-S?tze Betriebsanweisung:
R11:Leichtentzündlich.
R36/37/38:Reizt die Augen, die Atmungsorgane und die Haut.
S-S?tze Betriebsanweisung:
S24/25:Berührung mit den Augen und der Haut vermeiden.
S43:Zum L?schen . . . (vom Hersteller anzugeben) verwenden (wenn Wasser die Gefahr erh?ht, anfügen: "Kein Wasser verwenden").
S7/8:Beh?lter trocken und dicht geschlossen halten.
Beschreibung
Zirconium(II) hydride, ZrH2, is a molecular chemical compound, which has been produced by laser ablation and isolated at low temperature. Zirconium(II) hydride has a dihedral (C2v) structure. In zirconium(II) hydride, the formal oxidation states of hydrogen and zirconium are 21 and 12, respectively, since the electronegativity of zirconium is lower than that of hydrogen. The stability of metal hydrides with the formula MH2 (M 5 Ti-Hf) decreases as the atomic number increases.
Chemische Eigenschaften
Gray-black metallic powder. Stable
toward air and water.
Physikalische Eigenschaften
Grayish-black powder; density 5.60 g/cm
3; stable in water; soluble in dilute hydrofluoric acid; soluble in concentrated acids.
Verwenden
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
synthetische
Zirconium hydride may be prepared by heating zirconium oxide with magnesium in the presence of hydrogen: ZrO
2 + 2Mg + H
2 → ZrH
2 + 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.
Vorbereitung Methode
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.
Definition
Contains 1.7–2.1% combined hydrogen which can
be driven off in a vacuum above 600C.
Allgemeine Beschreibung
This product has been enhanced for energy efficiency.
Hazard
Flammable, dangerous fire risk, especially
in the presence of oxidizers.
Sicherheitsprofil
A powerful reducing
agent. Flammable when dry or wet. Very
dangerous to handle; can explode.
Incandesces when heated in air. See also
HYDRIDES and ZIRCONIUM
COMPOUNDS.
Zirconiumdihydrid Upstream-Materialien And Downstream Produkte
Upstream-Materialien
Downstream Produkte
