Nickel(II) carbonate

Preparation

The hexahydrate NiCO3•6H2O is claimed to form upon electrolysis of nickel metal under an atmosphere of carbon dioxide. Green and yellow forms of anhydrous NiCO3 form when aqueous nickel chloride solutions are heated under high pressures of carbon dioxide.

Structure and reactions

NiCO3 adopts a structure like calcite, consisting of nickel in an octahedral coordination geometry. A pentahydrate has also been characterized by X-ray crystallography. Also known as the mineral hellyerite, the solid consists of [Ni2(CO3)2(H2O)8] subunits with an extra water of hydration.

Nickel carbonates are hydrolyzed upon contact with aqueous acids to give solutions containing the ion [Ni(H2O)6]2+, liberating water and carbon dioxide in the process. Calcining (heating to drive off CO2 and water) of these carbonates gives nickel(II) oxide: :

The nature of the resulting oxide depends on the nature of the precursor. The oxide obtained from the basic carbonate is often most useful for catalysis.

Basic nickel carbonate can be made by treating solutions of nickel sulfate with sodium carbonate: :

The hydrated carbonate has been prepared by electrolytic oxidation of nickel in the presence of carbon dioxide: :

Uses

Nickel carbonates are used in some ceramic applications and as precursors to catalysts.

Natural occurrence

The natural nickel carbonate is hellyerite, mentioned above. Basic Ni carbonates also have some natural representatives.

References

References

1. "Nickel carbonate - Material Safety Data Sheet".
2. {{Sigma-Aldrich
3. Keith Lascelles, Lindsay G. Morgan, David Nicholls, Detmar Beyersmann, "Nickel Compounds" in Ullmann's Encyclopedia of Industrial Chemistry Wiley-VCH, Weinheim, 2005. {{doi. 10.1002/14356007.a17_235.pub2
4. O. Glemser. (1963). "Handbook of Preparative Inorganic Chemistry, 2nd Ed.". Academic Press.
5. Pertlik, F.. (1986). "Structures of hydrothermally synthesized cobalt(II) carbonate and nickel(II) carbonate". Acta Crystallographica Section C.
6. (2016). "Crystal Structure and Hydrate Water Content of Synthetic Hellyerite, NiCO₃·5.5H₂O". Zeitschrift für Anorganische und Allgemeine Chemie.
7. Handbook of Preparative Inorganic Chemistry, 2nd Ed. Edited by G. Brauer, Academic Press, 1963, NY. p. 1557.
8. "Gaspéite".