载体对镍基催化剂顺酐液相加氢性能的影响

Effect of support on catalytic performance of nickel-based catalysts used for liquid phase hydrogenation of maleic anhydride

分别以Zr O2、Si O2与Al2O3为载体,采用等体积浸渍法制备了Ni质量分数为15%的催化剂,考察了其催化顺酐液相加氢性能,并利用BET、XRD、H2-TPR以及TPO-MS等表征手段对催化剂进行了详细表征。结果表明,随载体不同各催化剂的加氢活性及选择性存在较大差异,Ni/Al2O3催化剂的C C键加氢活性最高,但其几乎没有C O加氢活性,催化顺酐加氢主产物为丁二酸酐。Ni/Zr O2催化剂具有最高的C O加氢活性,催化顺酐加氢主产物为γ-丁内酯,在反应温度为483 K,氢气压力为5 MPa的条件下反应8 h时,Ni/Zr O2催化剂的γ-丁内酯选择性达79.20%。催化剂的套用实验表明,Ni/Zr O2与Ni/Si O2催化剂具有高的使用稳定性,Ni/Al2O3催化剂则在套用过程中快速失活。顺酐加氢至γ-丁内酯的中间产物——丁二酸酐与催化剂间的相互作用是影响催化剂加氢选择性及使用稳定性的主要原因。

Nickel-based catalysts supported on ZrO2, SiO2, and Al2O3 supports, were prepared by incipient impregnation method and evaluated using liquid phase hydrogenation of maleic anhydride. BET,XRD,H2-TPR and TPO-MS were employed to characterize these catalysts. Their catalytic performance varied with supports used. Among all the catalysts, Ni/Al2O3 catalyst exhibited the highest activity for C C hydrogenation, while there was the lowest activity for C O hydrogenation. Ni/ZrO2 catalyst had the highest C O hydrogenation activity, and maleic anhydride conversion and γ-butyrolactone selectivity were 100% and 79.2% respectively under the reaction condition of 483 K, 5 MPa of H2 and 8 h of reaction time. The re-use experiment of catalyst demonstrated that the stability of catalyst in liquid phase hydrogenation of maleic anhydride was better for Ni/ZrO2 and Ni/SiO2 than Ni/Al2O3. Both selectivity and stability of catalysts could be explained by the interaction between succinic anhydride and catalyst.