US Patent 6933409 Amination of aromatic hydrocarbons and heterocyclic analogs thereof

Noble metal/reducible metal oxide catalysts effective for the direct amination of aromatic hydrocarbons and heterocyclic analogs thereof are disclosed. In one embodiment, the cataloxidant comprises a noble metal selected from Pd, Rh, Ir and/or Ru and a reducible metal oxide. In another embodiment, the cataloxidant comprises a noble metal and a reducible oxide of a metal selected from Ni, Mn, V, Ce, Th, Pr, Te, Re, Co, Fe, Cu and/or Bi. A preferred cataloxidant comprises one or more noble metals selected from Pd, Rh, Ir and/or Ru, in combination with nickel oxide and/or manganese oxide. In preferred applications, benzene can be aminated in the presence of the cataloxidants to form aniline. A benzene conversion of at least 5% is achieved, with more than 90% selectivity for aniline. Significantly, the cataloxidant can be regenerated without a substantial loss of performance.