Ni-Cu/Al_2O_3催化剂上顺酐液相选择加氢制丁二酸酐反应性能

Selective Hydrogenation of Maleic Anhydride to Succinic Anhydride in Liquid Phase over Ni-Cu/Al_2O_3 Catalyst

以Al2O3为载体,采用等体积浸渍法制备了一系列Ni-Cu/Al2O3催化剂,用于顺酐液相加氢反应,并结合低温N2物理吸-脱附、H2程序升温还原、H2程序升温脱附、X射线衍射、CO程序升温表面反应等表征结果,详细考察了催化剂中Cu含量对其催化性能的影响.结果表明,Cu的引入提高了活性组分Ni的分散度,促进了催化剂上C=C的加氢活性;同时,由于Ni-Cu双金属间的相互作用,明显抑制了催化剂表面C=O的加氢.当Cu含量为7%时,催化剂上顺酐加氢定向合成丁二酸酐的活性最高.在210oC,H2压力5.0MPa的条件下反应40min时,顺酐转化率与丁二酸酐选择性均达100%.

A series of Ni-Cu/Al2O3 catalyst samples were prepared by the wetness impregnation method and characterized by N2 physisorption, H2 temperature-programmed reduction, H2 temperature-programmed desorption, X-ray diffraction, and CO temperature-programmed surface reaction. Their catalytic performance in the liquid phase hydrogenation of maleic anhydride was investigated. The results indicated that the particle size of nickel crystallites was reduced, and the nickel species was well dispersed. Then, the C=C hydrogenation activity was significantly improved when the catalyst was promoted by Cu. However, due to the interaction between Ni and Cu, the C=O hydrogenation was retarded. The combination of the above two factors led to high selectivity for succinic anhydride over 15%Ni-7%Cu/Al2O3 catalyst. The conversion of maleic anhydride and selectivity for succinic anhydride reached 100% under the reaction conditions of 5 MPa hydrogen pressure and 210 oC for 40 min.