Cobalt borides are

inorganic compound An inorganic compound is typically a chemical compound that lacks carbon–hydrogen bonds⁠that is, a compound that is not an organic compound. The study of inorganic compounds is a subfield of chemistry known as ''inorganic chemistry''. Inorgan ...

s with the general formula Co_xB_y. The two main cobalt borides are CoB and Co₂B. These are refractory materials.

Applications

Materials science

Cobalt borides are known to be exceptionally resistant to oxidation, a

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which makes them useful in the field of

materials science Materials science is an interdisciplinary field of researching and discovering materials. Materials engineering is an engineering field of finding uses for materials in other fields and industries. The intellectual origins of materials sci ...

. For instance, studies suggest cobalt boride can increase the lifespan of

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parts when used as a

coating A coating is a covering that is applied to the surface of an object, or substrate. The purpose of applying the coating may be decorative, functional, or both. Coatings may be applied as liquids, gases or solids e.g. powder coatings. Paints ...

, imparting surfaces with higher

corrosion Corrosion is a natural process that converts a refined metal into a more chemically stable oxide. It is the gradual deterioration of materials (usually a metal) by chemical or electrochemical reaction with their environment. Corrosion engine ...

and

wear Wear is the damaging, gradual removal or deformation of material at solid surfaces. Causes of wear can be mechanical (e.g., erosion) or chemical (e.g., corrosion). The study of wear and related processes is referred to as tribology. Wear in ...

resistance. These properties have been exploited in the field of

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for the design of specialized

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Renewable energy

Cobalt boride has also been studied as a

catalyst Catalysis () is the increase in rate of a chemical reaction due to an added substance known as a catalyst (). Catalysts are not consumed by the reaction and remain unchanged after it. If the reaction is rapid and the catalyst recycles quick ...

for

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storage and

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technologies.

Organic synthesis

Cobalt boride is also an effective

hydrogenation Hydrogenation is a chemical reaction between molecular hydrogen (H2) and another compound or element, usually in the presence of a catalyst such as nickel, palladium or platinum. The process is commonly employed to redox, reduce or Saturated ...

catalyst used in

organic synthesis Organic synthesis is a branch of chemical synthesis concerned with the construction of organic compounds. Organic compounds are molecules consisting of combinations of covalently-linked hydrogen, carbon, oxygen, and nitrogen atoms. Within the gen ...

. In one study, cobalt boride was found to be the most selective

transition metal In chemistry, a transition metal (or transition element) is a chemical element in the d-block of the periodic table (groups 3 to 12), though the elements of group 12 (and less often group 3) are sometimes excluded. The lanthanide and actinid ...

based catalyst available for the production of

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amine In chemistry, amines (, ) are organic compounds that contain carbon-nitrogen bonds. Amines are formed when one or more hydrogen atoms in ammonia are replaced by alkyl or aryl groups. The nitrogen atom in an amine possesses a lone pair of elec ...

s via

nitrile reduction In nitrile reduction a nitrile is organic reduction, reduced to either an amine or an aldehyde with a suitable chemical reagent. Catalytic hydrogenation The Catalysis, catalytic hydrogenation of nitriles is often the most economical route available ...

, even exceeding other cobalt containing catalysts such as Raney cobalt.

Preparations

Materials coating

Cobalt boride is produced under high temperature such as 1500 °C. Coatings of cobalt boride on iron are produced by

boriding Boriding, also called boronizing, is the process by which boron is added to a metal or alloy. It is a type of surface hardening. In this process boron atoms are diffused into the surface of a metal component. The resulting surface contains metal ...

, which involves first introducing a coating of FeB, Fe₂B. On to this iron boride coating is deposited cobalt using a pack cementation process. Cobalt boride

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in the size range of 18 to 22 nm have also been produced.

Catalyst

When used as a catalyst, cobalt boride is prepared by reducing a cobalt salt, such as cobalt(II) nitrate, with

sodium borohydride Sodium borohydride, also known as sodium tetrahydridoborate and sodium tetrahydroborate, is an inorganic compound with the formula (sometimes written as ). It is a white crystalline solid, usually encountered as an aqueous basic solution. Sodi ...

. Prior to reduction, the

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of the catalyst is maximized by supporting the salt on another material; often this material is

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