改性γ-Al_2O_3担载Pt催化剂用于硝基苯加氢制对氨基苯酚

Synthesis of p-Aminophenol from Hydrogenation of Nitrobenzene over Pt Catalyst Supported on Modified γ-Al_2O_3

Pt/ γ Al 2O 3 M (M=La 2O 3, Y 2O 3, CeO 2 and TiO 2) catalysts with Pt content of 1% were prepared and used for synthesis of p aminophenol (PAP) from catalytic hydrogenation of nitrobenzene. It is found that the PAP yield over the unmodified Pt/ γ Al 2O 3 is 69 68% and the PAP yield over the Pt/ γ Al 2O 3 M catalysts modified with La 2O 3, Y 2O 3, CeO 2 and TiO 2 is increased to 81 06%, 77 47%, 79 82% and 83 34%, respectively. Pt/ γ Al 2O 3 TiO 2 M (M=La 2O 3, Y 2O 3, CeO 2) catalysts modified simultaneously by rare earth metal and TiO 2 were also prepared. The yield of PAP over these catalysts is higher than that over Pt/ γ Al 2O 3 but lower than that over Pt/ γ Al 2O 3 TiO 2 catalyst. The effects of different reductants on the catalytic properties of Pt/ γ Al 2O 3 TiO 2 were studied. The results show that hydrazine is the better reductant than H 2.