Palladium Calcium Carbonate
Alias: lindra catalyst
Cas No: 7440-05-3
Molecular formula: Pd/CaCO3
Carrier: calcium carbonate
Appearance: black particles
Application scope：
High selective hydrogenation of alkynes to alkenes
Palladium calcium carbonate, Lindlar catalyst, is a selective catalytic hydrogenation catalyst. Palladium is adsorbed on the carrier (calcium carbonate or barium sulfate) and a small amount of inhibitor (lead acetate or quinoline) is added. Solubility: insoluble in water, storage and transportation: Pd-CaCO3-PbO and Pd-BaSO4-quinoline are commonly used for sealed and dry preservation, and the palladium content is 5% ~ 10%. In the catalytic hydrogenation reaction using the catalyst, the hydrogen adds cis - alkene to the acetylene bond. For example, propargylic acid is reduced to cis-2-butenic acid (isobastanoic acid) and cis-oleic acid, respectively, with the same configuration as natural oleic acid. It is used in industry to improve the purity of ethylene. It was invented by a roche chemist, Herbert Lindlar. The original method was to reduce palladium chloride in calcium carbonate slurry and add lead acetate. In the catalytic hydrogenation reaction with lindela catalyst, only 1mol of hydrogen was added to the alkyne to obtain cis-olefin. In essence, lindra catalyst is an application of catalyst poisoning. Pb or PbO are both lead-containing substances and belong to heavy metals. Heavy metals can poison catalysts. When the catalyst is poisoned, it is equivalent to inhibiting the activity of the catalyst, so that the alkynes cannot be completely converted into alkanes, but into alkenes. This is also a method of reducing alkynes or forming alkenes.
Reaction mechanism: alkynes are linear in shape because of two PI bonds. When the lindela catalyst is encountered, two hydrogen atoms are added to each end of the alkyne triple bond. And it is the plane that is parallel to the sigma bond and adds to it, so it forms cis-olefin.
P&C parameters:
|
Palladium content |
0.3%，0.5%，1.0%，5% |
|
PH value (10% suspension) |
8.0-10.0 |
|
Molecular formula |
Pd/CaCO3 |
|
CAS no. |
7440-05-3 |
| Specific surface area |
≥5.00m2/g |
| Bulk density |
0.80～0.85 g/ml |
|
105 ℃ volatile matter content |
≥0.4% |
|
Insoluble content of hydrochloric acid |
≤0.10% |
|
Sedimentation volume |
≥2.8ml/g |
|
Iron (Fe) content |
≤0.08% |
|
Manganese (Mn) content |
≤0.006% |
|
Screenings |
25umTest sieve≤0.30% |
陕公网安备 61030502000254号