page_title: Raney nickel
section_title: Properties
hierarchical_section_title: Raney nickel / Properties
caption_attribution_description: English: A close-up of Raney nickel. Small cracks of approximately 1-100 nm width are seen within the crystals, causing the increased surface area.
context_page_description: Raney nickel, also called spongy nickel, is a fine-grained solid composed mostly of nickel derived from a nickel–aluminium alloy. Several grades are known, of which most are gray solids. Some are pyrophoric, most are used as air-stable slurries. Raney nickel is used as a reagent and as a catalyst in organic chemistry. It was developed in 1926 by American engineer Murray Raney for the hydrogenation of vegetable oils.
context_section_description: Macroscopically, Raney nickel is a finely divided, grey powder. Microscopically, each particle of this powder is a three-dimensional mesh, with pores of irregular size and shape of which the vast majority is created during the leaching process. Raney nickel is notable for being thermally and structurally stable, as well as having a large Brunauer-Emmett-Teller (BET ) surface area. These properties are a direct result of the activation process and contribute to a relatively high catalytic activity.
  The surface area is typically determined by a BET measurement using a gas that is preferentially adsorbed on metallic surfaces, such as hydrogen. Using this type of measurement, almost all the exposed area in a particle of the catalyst has been shown to have Ni on its surface. Since Ni is the active metal of the catalyst, a large Ni surface area implies a large surface is available for reactions to occur simultaneously, which is reflected in an increased catalyst activity. Commercially available Raney nickel has an average Ni surface area of 100 m² per gram of catalyst.
  A high catalytic activity, coupled with the fact that hydrogen is absorbed within the pores of the catalyst during activation, makes Raney nickel a useful catalyst for many hydrogenation reactions. Its structural and thermal stability (i.e., it does not decompose at high temperatures) allows its use under a wide range of reaction conditions. Additionally, the solubility of Raney nickel is negligible in most common laboratory solvents, with the exception of mineral acids such as hydrochloric acid, and its relatively high density (about 6.5 g cm⁻³) also facilitates its separation from a liquid phase after a reaction is completed.
caption: A close-up of Raney nickel. Small cracks of approximately 1-100 nm width are seen within the crystals, causing the increased surface area.
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