Abstract: The invention relates to a process for preparing aromatic amines by hydrogenation of nitroaromatics in the presence of catalysts, in which a fluid reaction mixture which comprises amines and from which the catalysts are separated off is formed in a reactor. After the catalysts have been separated off, a measurement of the absorption of UV/VIS radiation by the reaction mixture is carried out to determine the concentration of nitro and nitroso compounds in the reaction mixture.

Abstract: Novel ruthenium catalysts can be obtained by: i) treating a support material based on amorphous silicon dioxide one or more times with a halogen-free aqueous solution of a low molecular weight ruthenium compound and subsequently drying the treated support material at below 200° C., ii) reducing the solid obtained in i) by means of hydrogen at from 100 to 350° C., where step ii) is carried out directly after step i). These catalysts can be used for the catalytic hydrogenation of monosaccharides and disaccharides to produce sugar alcohols, with the exception of sorbitol.

Abstract: The invention relates to a process for preparing aromatic amines by hydrogenation of nitroaromatics in the presence of catalysts, in which a fluid reaction mixture which comprises amines and from which the catalysts are separated off is formed in a reactor. After the catalysts have been separated off, a measurement of the absorption of UV/VIS radiation by the reaction mixture is carried out to determine the concentration of nitro and nitroso compounds in the reaction mixture.

Abstract: Sugar alcohols are prepared by catalytically hydrogenating the corresponding monosaccharides and oligosaccharides in the liquid phase over a heterogeneous ruthenium catalyst, with the exception of the preparation of sorbitol, wherein the heterogeneous ruthenium catalyst is prepared by: i) treating a support material based on amorphous silicon dioxide comprising at least 95% by weight of silicon dioxide and less than 1% by weight aluminum oxide, calculated as Al2O3, one or more times with a halogen-free aqueous solution of a low molecular weight ruthenium compound which is a ruthenium (III) salt or a metal ruthenate and subsequently drying the treated support material at a temperature below 200° C., and ii) reducing the solid obtained in i) by means of hydrogen at a temperature ranging from 100 to 350° C., wherein step ii) is carried out directly after step i), and wherein the ruthenium content in the catalyst ranges from 0.1 to 5% by weight, based on the support material.

Abstract: A catalyst comprising nickel on a TiO2 support is obtainable by coprecipitation of nickel and at least one further metal selected from among Si, Zr, Hf, alkaline earth metals, Y, La and Ce, and optionally at least one dopant metal selected from groups 5 to 11 of the Periodic Table of the Elements, from a solution in which the corresponding metal salts are present onto a particulate TiO2 support, subsequent drying, calcination and reduction and optionally passivation to give the nickel-containing catalyst. It is used, in particular, for the hydrogenation of nitroaromatic compounds.

Abstract: The invention relates to a process for preparing aromatic amines by hydrogenation of nitroaromatics in the presence of catalysts, in which a fluid reaction mixture which comprises amines and from which the catalysts are separated off is formed in a reactor. After the catalysts have been separated off, a measurement of the absorption of UV/VIS radiation by the reaction mixture is carried out to determine the concentration of nitro and nitroso compounds in the reaction mixture.

Abstract: In a process for hydrogenating at least one organic compound, the organic compound or compounds is/are brought into contact with a hydrogen-containing gas in the presence of a catalyst which comprises, as active metal, ruthenium either alone or together with at least one further metal of transition group I, VII or VIII of the Periodic Table applied to a support material based on amorphons silicon dioxide and is obtainable by: i) a single or multiple treatment of a support material based on amorphous silicon dioxide with a halogen-free aqueous solution of a low molecular weight ruthenium compound and subsequent drying of the treated support material at below 200° C., ii) reduction of the solid obtained in i) by means of hydrogen at from 100 to 350° C., with step ii) being carried out directly after step i).

Abstract: The invention relates to a method for producing hydrocarbons having a modified carbon skeleton by reacting aliphatic hydrocarbons a) with themselves, b) with another aliphatic hydrocarbon or c) with aromatic alkyl substituted hydrocarbons, in the presence of a metal organic catalyst or the hybrid thereof, at a temperature of between 20–400° C. and a pressure of between 0.2–100 bars, wherein the reaction takes place in the presence of hydrogen.

Abstract: The invention provides a process for preparing amines by catalytic hydrogenation of nitroaromatics and subsequent removal of the catalysts from the reaction mixture, which contains at least one aromatic amine and water, which comprises carrying out the removal of the catalysts by means of membrane filtration, which is carried out at a pressure on the suspension side of from 5 to 50 bar, a pressure difference between the suspension side and the permeate side of at least 0.3 bar and a flux rate on the suspension side of from 1 to 6 m/s.

Abstract: The catalyst can be prepared by reduction of a precursor of a hydrogenation-active metal, which may be present on an oxidic support, by reaction with at least one compound of the formula (I) HnM(OR)3-n??(I) where M is Ga or Al, R is CR?3 or SiR?3 where R? is C1-20-alkyl, and n is 1 or 2, or dimers or oligomers thereof, wherein the crystallite size of the hydrogenation-active metal in the finished catalyst is from 5 to 30, preferably 5 to 15 nm.

Abstract: The catalyst can be prepared by reduction of a precursor of a hydrogenation-active metal, which may be present on an oxidic support, by reaction with at least one compound of the formula (I) HnM(OR)3?n??(I) where M is Ga or Al, R is CR?3 or SiR?3 where R? is C1-20-alkyl, and n is 1 or 2, or dimers or oligomers thereof, wherein the crystallite size of the hydrogenation-active metal in the finished catalyst is from 5 to 30, preferably 5 to 15 nm.

Abstract: A process is described for preparing sorbitol by catalytic hydrogenation of a monosaccharide forming sorbitol on hydrogenation in the liquid phase, which comprises the catalyst being obtainable by: i) single or multiple treatment of an amorphous silicon dioxide based support material with a halogen-free aqueous solution of a low-molecular-weight ruthenium compound and subsequent drying of the treated support material at below 200° C., ii) reducing the solid obtained in i) with hydrogen at from 100 to 350° C., step ii) being carried out immediately after step i).

Abstract: The invention provides a process for preparing amines by catalytic hydrogenation of nitroaromatics and subsequent removal of the catalysts from the reaction mixture, which contains at least one aromatic amine and water, which comprises carrying out the removal of the catalysts by means of membrane filtration, which is carried out at a pressure on the suspension side of from 5 to 50 bar, a pressure difference between the suspension side and the permeate side of at least 0.3 bar and a flux rate on the suspension side of from 1 to 6 m/s.

Abstract: Coated catalysts which comprise at least one catalytically active metal on an inorganic or carbon support are prepared by mixing a solid, preferably vaporizable, precursor material of the at least one catalytically active metal with the inorganic support and heating the mixture obtained in this way with further mixing until no more separate solid precursor material is present, preferably to a temperature at which the precursor material vaporizes. Such coated catalysts may in particular be used in hydrogenations.

Abstract: In a process for hydrogenating at least one organic compound, the organic compound or compounds is/are brought into contact with a hydrogen-containing gas in the presence of a catalyst which comprises, as active metal, ruthenium either alone or together with at least one further metal of transition group I, VII or VIII of the Periodic Table applied to a support material based on amorphons silicon dioxide and is obtainable by:

Abstract: Novel ruthenium catalysts can be obtained by:

Abstract: Cycloaliphatic compounds I which have side chains containing epoxide groups are prepared by heterogeneously catalyzed hydrogenation of a compound II which comprises at least one carbocyclic aromatic group and at least one side chain containing at least one epoxide group over a ruthenium catalyst, wherein the ruthenium catalyst is obtainable by

Abstract: A process is described for preparing sorbitol by catalytic hydrogenation of a monosaccharide forming sorbitol on hydrogenation in the liquid phase, which comprises the catalyst being obtainable by:

Abstract: A catalyst comprising nickel on a TiO2 support is obtainable by coprecipitation of

Abstract: The invention relates to a method for producing hydrocarbons having a modified carbon skeleton by reacting aliphatic hydrocarbons a) with themselves, b) with another aliphatic hydrocarbon or c) with aromatic alkyl substituted hydrocarbons, in the presence of a metal organic catalyst or the hybrid thereof, at a temperature of between 20-400° C. and a pressure of between 0.2-100 bars, wherein the reaction takes place in the presence of hydrogen.