A catalyst composition for hydrogenating 4,4-methylenedianiline derivatives is provided. The catalyst composition includes a carrier including aluminum oxide and magnesium oxide, a rhodium-ruthenium active layer loaded on the surface of the carrier, and a solvent including an organic amine. The weight percentage of magnesium oxide in the carrier is between 12% and 30%. A method for preparing 4,4-methylene bis(cyclohexylamine) derivatives using the catalyst composition is also provided.

A catalyst composition for hydrogenating 4,4-methylenedianiline derivatives is provided. The catalyst composition includes a carrier including aluminum oxide and magnesium oxide, a rhodium-ruthenium active layer loaded on the surface of the carrier, and a solvent including an organic amine. The weight percentage of magnesium oxide in the carrier is between 12% and 30%. A method for preparing 4,4-methylene bis(cyclohexylamine) derivatives using the catalyst composition is also provided.

Process for hydrogenating toluenediamine (TDA) tar containing TDA and high boilers relative to TDA, including the step of contacting the toluenediamine tar with a heterogeneous hydrogenation catalyst comprising at least one metal selected from the group consisting of Ni, Co, Ru, Pd, Pt on at least one catalyst support selected from the group consisting of carbon, TiO.sub.2 and ZrO.sub.2, and with hydrogen under hydrogenating conditions.

Process for hydrogenating toluenediamine (TDA) tar containing TDA and high boilers relative to TDA, including the step of contacting the toluenediamine tar with a heterogeneous hydrogenation catalyst comprising at least one metal selected from the group consisting of Ni, Co, Ru, Pd, Pt on at least one catalyst support selected from the group consisting of carbon, TiO.sub.2 and ZrO.sub.2, and with hydrogen under hydrogenating conditions.

Process for hydrogenating toluenediamine (TDA) tar containing TDA and high boilers relative to TDA, including the step of contacting the toluenediamine tar with a heterogeneous hydrogenation catalyst comprising at least one metal selected from the group consisting of Ni, Co, Ru, Pd, Pt on at least one catalyst support selected from the group consisting of carbon, TiO.sub.2 and ZrO.sub.2, and with hydrogen under hydrogenating conditions.

The present invention relates to a process for hydrogenating a mixture (G1) in the presence of a catalyst, where the mixture (G1) comprises at least one colorless amine and at least one color-imparting component. As a result of the hydrogenation step, the at least one color-imparting component is firstly partially, preferably fully, hydrogenated, while the colorless amine, in particular aniline, is not hydrogenated or hydrogenated to only a very small extent. The color-imparting components which cause the discoloration of the amine which is itself in principle colorless are thus removed by hydrogenation, as a result of which purification of the colorless amine or the mixture (G1) is achieved.

The present invention relates to a process for hydrogenating a mixture (G1) in the presence of a catalyst, where the mixture (G1) comprises at least one colorless amine and at least one color-imparting component. As a result of the hydrogenation step, the at least one color-imparting component is firstly partially, preferably fully, hydrogenated, while the colorless amine, in particular aniline, is not hydrogenated or hydrogenated to only a very small extent. The color-imparting components which cause the discoloration of the amine which is itself in principle colorless are thus removed by hydrogenation, as a result of which purification of the colorless amine or the mixture (G1) is achieved.

The present invention relates to a method for hydrogenating aromatic compounds with hydrogen in the presence of a catalyst, in which the catalyst comprises ruthenium on a zirconium oxide support material, and also the use of a catalyst comprising ruthenium on a zirconium oxide support material for hydrogenating aromatic compounds.

The present invention relates to a method for hydrogenating aromatic compounds with hydrogen in the presence of a catalyst, in which the catalyst comprises ruthenium on a zirconium oxide support material, and also the use of a catalyst comprising ruthenium on a zirconium oxide support material for hydrogenating aromatic compounds.

The present invention relates to a method for hydrogenating aromatic compounds with hydrogen in the presence of a catalyst, in which the catalyst comprises ruthenium on a zirconium oxide support material, and also the use of a catalyst comprising ruthenium on a zirconium oxide support material for hydrogenating aromatic compounds.