Palladium on carbon
Encyclopedia
Palladium on carbon, often referred to as Pd/C, is a form of palladium
used for catalysis
. It is usually used for catalytic hydrogenation
s in organic chemistry
. When the metal is distributed over finely divided carbon the surface area is larger and the catalyst more reactive.
Palladium-on-carbon has also been used as the palladium(0) catalyst in the Suzuki reaction
, Stille reaction
, and related reactions.
of 7440-05-3. It can also be prepared in the laboratory. In a typical procedure, palladium(II) chloride
and hydrochloric acid
are added to nitric acid
-washed activated carbon
. This composite is then dried, and the palladium(II) is reduced to palladium(0) with hydrogen gas, and washed. The palladium loading is typically between 5% and 10%.
Palladium
Palladium is a chemical element with the chemical symbol Pd and an atomic number of 46. It is a rare and lustrous silvery-white metal discovered in 1803 by William Hyde Wollaston. He named it after the asteroid Pallas, which was itself named after the epithet of the Greek goddess Athena, acquired...
used for catalysis
Catalysis
Catalysis is the change in rate of a chemical reaction due to the participation of a substance called a catalyst. Unlike other reagents that participate in the chemical reaction, a catalyst is not consumed by the reaction itself. A catalyst may participate in multiple chemical transformations....
. It is usually used for catalytic hydrogenation
Hydrogenation
Hydrogenation, to treat with hydrogen, also a form of chemical reduction, is a chemical reaction between molecular hydrogen and another compound or element, usually in the presence of a catalyst. The process is commonly employed to reduce or saturate organic compounds. Hydrogenation typically...
s in organic chemistry
Organic chemistry
Organic chemistry is a subdiscipline within chemistry involving the scientific study of the structure, properties, composition, reactions, and preparation of carbon-based compounds, hydrocarbons, and their derivatives...
. When the metal is distributed over finely divided carbon the surface area is larger and the catalyst more reactive.
Palladium-on-carbon has also been used as the palladium(0) catalyst in the Suzuki reaction
Suzuki reaction
The Suzuki reaction is the organic reaction of an aryl- or vinyl-boronic acid with an aryl- or vinyl-halide catalyzed by a palladium complex. It is widely used to synthesize poly-olefins, styrenes, and substituted biphenyls, and has been extended to incorporate alkyl bromides...
, Stille reaction
Stille reaction
The Stille reaction is a chemical reaction coupling an organotin compound with an sp2-hybridized organic halide catalyzed by palladium. The reaction is widely used in organic synthesis....
, and related reactions.
Preparation
Palladium on carbon is commercially available, with a CAS numberChemical Abstracts Service
Chemical Abstracts is a periodical index that provides summaries and indexes of disclosures in recently published scientific documents. Approximately 8,000 journals, technical reports, dissertations, conference proceedings, and new books, in any of 50 languages, are monitored yearly, as are patent...
of 7440-05-3. It can also be prepared in the laboratory. In a typical procedure, palladium(II) chloride
Palladium(II) chloride
Palladium chloride, also known as palladium dichloride, are the chemical compounds with the formula PdCl2. PdCl2 is a common starting material in palladium chemistry – palladium-based catalysts are of particular value in organic synthesis. It is prepared by chlorination of...
and hydrochloric acid
Hydrochloric acid
Hydrochloric acid is a solution of hydrogen chloride in water, that is a highly corrosive, strong mineral acid with many industrial uses. It is found naturally in gastric acid....
are added to nitric acid
Nitric acid
Nitric acid , also known as aqua fortis and spirit of nitre, is a highly corrosive and toxic strong acid.Colorless when pure, older samples tend to acquire a yellow cast due to the accumulation of oxides of nitrogen. If the solution contains more than 86% nitric acid, it is referred to as fuming...
-washed activated carbon
Activated carbon
Activated carbon, also called activated charcoal, activated coal or carbo activatus, is a form of carbon that has been processed to make it extremely porous and thus to have a very large surface area available for adsorption or chemical reactions.The word activated in the name is sometimes replaced...
. This composite is then dried, and the palladium(II) is reduced to palladium(0) with hydrogen gas, and washed. The palladium loading is typically between 5% and 10%.