Adkins catalyst
Encyclopedia
Copper chromite is a complex inorganic composition Cu2Cr2O5, but often containing barium oxide that is used to catalyse certain reactions in organic synthesis
. It was first described in 1908. A variety of composition are recognized including Cr2CuO4·CuO·BaCrO4 (chemical abstracts registry number is 99328-50-4) and Cr2Cu2O5 (CAS# 12053-18-8). The latter is sometimes intentionally poisoned with quinoline
, when the catalyst is used for decarboxylation
reactions. The catalyst was developed in North America by Homer Burton Adkins
and Wilbur Arthur Lazier partly based on interrogation of German
chemists after World War II
in relation to the Fischer-Tropsch process
. For this reason it is referred to as the Lazier catalyst.
The catalyst Cr2CuO4·CuO·BaCrO4 is prepared by addition of a solution containing both barium nitrate
and copper(II) nitrate
to a solution of ammonium chromate
. This resulting precipitate is calcined at 350-400 °C.
Reactions involving hydrogen are conducted at relatively high gas pressure (135 atm
) and high temperatures (150-300 °C) in a so-called hydrogenation bomb. More active catalysts requiring less vigrous conditions are known but are typically derived from more expensive metals, such as platinum
.
Organic synthesis
Organic synthesis is a special branch of chemical synthesis and is concerned with the construction of organic compounds via organic reactions. Organic molecules can often contain a higher level of complexity compared to purely inorganic compounds, so the synthesis of organic compounds has...
. It was first described in 1908. A variety of composition are recognized including Cr2CuO4·CuO·BaCrO4 (chemical abstracts registry number is 99328-50-4) and Cr2Cu2O5 (CAS# 12053-18-8). The latter is sometimes intentionally poisoned with quinoline
Quinoline
Quinoline is a heterocyclic aromatic organic compound. It has the formula C9H7N and is a colourless hygroscopic liquid with a strong odour. Aged samples, if exposed to light, become yellow and later brown...
, when the catalyst is used for decarboxylation
Decarboxylation
Decarboxylation is a chemical reaction that releases carbon dioxide . Usually, decarboxylation refers to a reaction of carboxylic acids, removing a carbon atom from a carbon chain. The reverse process, which is the first chemical step in photosynthesis, is called carbonation, the addition of CO2 to...
reactions. The catalyst was developed in North America by Homer Burton Adkins
Homer Burton Adkins
Dr. Homer Burton Adkins, Ph.D. was an American chemist who studied the hydrogenation of organic compounds.-Life and work:...
and Wilbur Arthur Lazier partly based on interrogation of German
Germany
Germany , officially the Federal Republic of Germany , is a federal parliamentary republic in Europe. The country consists of 16 states while the capital and largest city is Berlin. Germany covers an area of 357,021 km2 and has a largely temperate seasonal climate...
chemists after World War II
World War II
World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...
in relation to the Fischer-Tropsch process
Fischer-Tropsch process
The Fischer–Tropsch process is a set of chemical reactions that convert a mixture of carbon monoxide and hydrogen into liquid hydrocarbons. The process, a key component of gas to liquids technology, produces a petroleum substitute, typically from coal, natural gas, or biomass for use as synthetic...
. For this reason it is referred to as the Lazier catalyst.
The catalyst Cr2CuO4·CuO·BaCrO4 is prepared by addition of a solution containing both barium nitrate
Barium nitrate
Barium nitrate with chemical formula Ba2 is a salt of barium and the nitrate ion.Barium nitrate exists as a white solid at room temperature. It is soluble in water, and like other soluble barium compounds, is toxic and should be handled with care...
and copper(II) nitrate
Copper(II) nitrate
Copper nitrate is the chemical compound with the formula Cu2. Commonly referred to simply as copper nitrate, the anhydrous form is a blue, crystalline solid...
to a solution of ammonium chromate
Chromate
Chromate salts contain the chromate anion, CrO42−. Dichromate salts contain the dichromate anion, Cr2O72−. They are oxyanions of chromium in the oxidation state +6. They are moderately strong oxidizing agents.- Chemical properties :...
. This resulting precipitate is calcined at 350-400 °C.
Illustrative reactions
- HydrogenolysisHydrogenolysisHydrogenolysis is a chemical reaction whereby a carbon–carbon or carbon–heteroatom single bond is cleaved or undergoes "lysis" by hydrogen. The heteroatom may vary, but it usually is oxygen, nitrogen, or sulfur. A related reaction is hydrogenation, where hydrogen is added to the molecule, without...
of esterEsterEsters are chemical compounds derived by reacting an oxoacid with a hydroxyl compound such as an alcohol or phenol. Esters are usually derived from an inorganic acid or organic acid in which at least one -OH group is replaced by an -O-alkyl group, and most commonly from carboxylic acids and...
compounds to the corresponding alcoholAlcoholIn chemistry, an alcohol is an organic compound in which the hydroxy functional group is bound to a carbon atom. In particular, this carbon center should be saturated, having single bonds to three other atoms....
s. For example, sebacion, derived from the acyloin condensationAcyloin condensationAcyloin condensation is a reductive coupling of two carboxylic esters using metallic sodium to yield an α-hydroxyketone, also known as an acyloin....
of dimethyl sebacateSebacic acidSebacic acid is a dicarboxylic acid with structure 8, and is naturally occurring.In its pure state it is a white flake or powdered crystal...
, is hydrogenated to 1,2-cyclodecanediol by this catalyst. PhenanthrenePhenanthrenePhenanthrene is a polycyclic aromatic hydrocarbon composed of three fused benzene rings. The name phenanthrene is a composite of phenyl and anthracene. In its pure form, it is found in cigarette smoke and is a known irritant, photosensitizing skin to light...
is also reduced, at the 9,10 position. - HydrogenolysisHydrogenolysisHydrogenolysis is a chemical reaction whereby a carbon–carbon or carbon–heteroatom single bond is cleaved or undergoes "lysis" by hydrogen. The heteroatom may vary, but it usually is oxygen, nitrogen, or sulfur. A related reaction is hydrogenation, where hydrogen is added to the molecule, without...
of 2-furfuryl alcoholFurfuryl alcoholFurfuryl alcohol, also called 2-furylmethanol or 2-furancarbinol, is an organic compound containing a furan substituted with a hydroxymethyl group. It is a clear colorless liquid when pure, but becomes amber colored upon prolonged standing. It possesses a faint burning odor and a bitter taste. ...
to 1,5-pentanediol1,5-Pentanediol1,5-Pentanediol is the organic compound with the formula HOCH2CH2CH2CH2CH2OH. Like other diols, this viscous liquid is used as plasticizer and also forms polyesters that are used as emulsifying agents and resin intermediates...
at 250-300 °C under 3300-6000 psi of H2. - DecarboxylationDecarboxylationDecarboxylation is a chemical reaction that releases carbon dioxide . Usually, decarboxylation refers to a reaction of carboxylic acids, removing a carbon atom from a carbon chain. The reverse process, which is the first chemical step in photosynthesis, is called carbonation, the addition of CO2 to...
of α-phenylcinnamic acid to cis-stilbeneStilbene-Stilbene, is a diarylethene, i.e., a hydrocarbon consisting of a trans ethene double bond substituted with a phenyl group on both carbon atoms of the double bond. The name stilbene is derived from the Greek word stilbos, which means shining....
.
Reactions involving hydrogen are conducted at relatively high gas pressure (135 atm
Atmosphere (unit)
The standard atmosphere is an international reference pressure defined as 101325 Pa and formerly used as unit of pressure. For practical purposes it has been replaced by the bar which is 105 Pa...
) and high temperatures (150-300 °C) in a so-called hydrogenation bomb. More active catalysts requiring less vigrous conditions are known but are typically derived from more expensive metals, such as platinum
Platinum
Platinum is a chemical element with the chemical symbol Pt and an atomic number of 78. Its name is derived from the Spanish term platina del Pinto, which is literally translated into "little silver of the Pinto River." It is a dense, malleable, ductile, precious, gray-white transition metal...
.