负载Pd-Fe双金属催化剂催化含氟芳香硝基化合物的选择性加氢

Selective Hydrogenation of Fluoronitroaromatic Compounds over Supported Palladium-Iron Catalysts

采用浸渍法制备了负载 Pd-Fe 双金属催化剂,考察了催化剂常压下催化3-氯-4-氟硝基苯的选择性加氢性能。结果表明,用硼氢化钾还原,在500℃焙烧4 h,钯和铁的质量分数分别为5%和0.2%的 TiO_2负载 Pd-Fe 催化剂,具有很好的催化活性和选择性。在3-氯-4-氟硝基苯0.1 mol,催化剂0.26 g,无水乙醇80 mL,50℃,0.1 MPa 和反应2 h 的条件下,TiO_2负载 Pd-Fe 催化剂催化3-氯-4-氟硝基苯加氢反应,反应产率98.1%,3-氯-4-氟苯胺选择性99.1%。TiO_2负载的 Pd-Fe 催化剂用于催化其他含氟芳香硝基化合物的常压加氢也表现出很高的催化活性和选择性,无脱卤现象。

Selective hydrogenation of 3-chloro-4-fluoronitrobenzene over supported palladium catalysts containing transition metals at normal pressure was studied. The results showed that TiO2 supported Pd-Fe catalyst exhibited high catalytic activity and selectivity for hydrogenation of 3-chloro-4-fluoroni- trobenzene when the catalyst with mass fraction of Pd 5% and mass fraction of Fe 0.2% was calcined for 4 h at 500℃ and reduced by KBH4. Under the conditions of 3-ehloro-4-fluoronitrobenzene 0. 1mol, catalyst 0. 26g, ethanol 80 mL, 50℃ and H2 partial pressure 0.1 MPa, the reaction yield and selectivity of 3-chloro-4-fluoroaniline were 98.1% and 99.1% respectively, in the presence of Pd-Fe/TiO2 catalyst. The catalyst also exhibited high activity and selectivity for the hydrogenation of other fluoronitroaromatic compounds. Meanwhile, the dehalogenation product wasn＇t found.