US 6,090,746 A · Process for producing tenside-stabilized colloids of mono- and bimetals of the group VIII and Ib of the periodic system in the form of precursors for catalysts which are isolable and water soluble at high concentration

Abstract

The invention relates to a process for producing tenside-stabilized colloids of mono- and bimetals of the group VIII and Ib of the periodic system which are isolable in the form of powder and which are soluble at a concentration of at least 10 mg atom of metal/l of water, from metal salts in the presence of strongly hydrophilic tensides with hydrotriorganoborates in THF, or with simple chemical reduction agents like hydrogen or alkali formate in water and alcohols, respectively. Furthermore, the subject matter of the invention is the use of tenside-stabilized colloids which are produced according to this process as precursor for supported catalysts for the selective cis-hydrogenation of C--C triple bonds, for the selective hydrogenation of functional groups at the aromatic nucleus, for the selective hydrogenation of benzene to cyclohexene, for the partial oxidation of the primary alcohol functionality in carbohydrates, as well as for use as a precursor for electrocatalysts in fuel cells.

Claims25

Dependent claims

A process for producing water-soluble, surfactant-stabilized colloids of mono- and bimetals of groups VIII and Ib of the periodic system, said colloids having particles ranging in sizes of from 1 to 10 nm, said process comprising:

a) reacting metal salts with a chemical reducing agent in the presence of a strongly hydrophilic surfactant selected from the group consisting of amphiphilic betaines, cationic surfactants, fatty alcohol polyglycol ethers, polyoxyethylene-carbohydrate-fatty alkyl esters, anionic surfactants and amphiphilic sugar surfactants, in water in the absence of an organic solvent, at a temperature between 0.degree. C. and 100.degree. C., at normal pressure, and optionally with the addition of an alkali carbonate and/or ammonium chloride to yield an aqueous solution comprising said colloids;
and
b) isolating said colloids from said aqueous solution in a concentration of >100 mg atom metal/liter.

Water-soluble, surfactant-stabilized colloids of mono- and bimetals of groups VIII and Ib of the periodic system, said colloids having particles ranging in sizes of from 1 to 10 nm, said colloids being covered on a surface area thereof with a strongly hydrophilic surfactant selected from the group consisting of amphiphilic betaines, cationic surfactants, fatty alcohol polyglycol ethers, polyoxyethylene-carbohydrate-fatty alkyl esters, anionic surfactants and amphiphilic sugar surfactants, and said colloids being obtainable by a process comprising:

a) reacting metal salts with a chemical reducing agent in the presence of a strongly hydrophilic surfactant selected from the group consisting of amphiphilic betaines, cationic surfactants, fatty alcohol polyglycol ethers, polyoxyethylene-carbohydrate-fatty alkyl esters, anionic surfactants and amphiphilic sugar surfactants, in water in the absence of an organic solvent, at a temperature between 0.degree. C. and 100.degree. C., at normal pressure, and optionally with the addition of an alkali carbonate and/or ammonium chloride to yield an aqueous solution comprising said colloids;
and
b) isolating said colloids from said aqueous solution in a concentration of >100 mg atom metal/liter.

Dependencies are inferred from the claim text.

Process for producing tenside-stabilized colloids of mono- and bimetals of the group VIII and Ib of the periodic system in the form of precursors for catalysts which are isolable and water soluble at high concentration

Life of this patent

Process for producing tenside-stabilized colloids of mono- and bimetals of the group VIII and Ib of the periodic system in the form of precursors for catalysts which are isolable and water soluble at high concentration

Life of this patent

Abstract

Claims25