| 摘要 |
An iron-modified, platinum hydrogenation catalyst useful for the reduction of aromatic nitro compounds is provided. The catalyst, having improved distribution of the metallic components on an oleophilic carbon support as shown by ESCA analysis, is prepared by depositing a platinum compound (oxide, hydroxide or carbonate) on the carbon support at a temperature in the range of 55 DEG -95 DEG C., preferably 90 DEG -95 DEG C., and then reducing the compound to platinum metal, preferably with formaldehyde, at a temperature less than about 35 DEG C. The iron in the catalyst is present and deposited as its oxide or hydroxide either at the same temperature as the platinum compound or at a temperature less than about 35 DEG C. Using such a catalyst to reduce halogen-substituted nitro aromatic compounds to the corresponding amines results in low dehalogenation, low tar formation and hydroxylamine accumulation. For nonhalogenated nitro aromatic reductions, the catalyst minimizes ring reduction. |
