采用化学还原法制备Ni-B和Ni-Cu-B非晶态合金催化剂,考察镍源、硼镍物质的量比、铜添加量对催化剂催化加氢性能的影响.结果表明,制备催化剂的最佳条件为:氯化镍为镍源,硼镍物质的量比为4:1(mol/mol),xCu=5%(mol)(xCu=nCu/(nCu+nNi)).助剂Cu的添加增大了催化剂的吸氢能力,使得Ni-Cu-B中的金属Ni为富电子状态,而B为缺电子状态,更利于加氢反应.该反应的最佳工艺条件为反应温度160℃、氢气分压0.8 MPa以及反应时间6 h.对Ni-Cu-B非晶态催化剂的稳定性进行了测试,研究了该催化剂的失活机理,研究结果显示反应5次后催化剂的转化率和选择性分别为99.2%和51.0%,与新鲜催化剂相比(转化率和选择性分别为100%,52.9%)分别减少了0.8%和1.9%,说明催化剂在循环使用5次后活性基本保持不变;通过对反应5次后的催化剂进行表征分析发现,催化剂的比表面积和孔容均减少,并产生团聚现象,但其非晶态结构不变,说明催化剂活性缓慢降低的原因可能是反应中产生的副产物覆盖了催化剂的活性中心,导致反应物分子接触到催化剂活性中心的几率减少.%Ni-Cu-B amorphous catalysts were prepared by a chemical reduction method for selective hydrogenation of furfural to cyclopentanone. Effects of nickel source, molar ratio of boron to nickel, and the amount of Cu addition on catalytic performance were investigated. The results show that the optimum conditions for the preparation of Ni-Cu-B amorphous alloy catalysts are: nickel chloride as the nickel source, the molar ratio of boron to nickel is 4:1 andxCu= 5%(mol) (xCu=nCu/(nCu+nNi) ). The addition of promoter Cu increases hydrogen absorption capacity and changes chemical environment of the catalysts. Some electron transfers from alloying B to metallic Ni and makes Ni electron-rich, which facilitates the hydrogenation reaction. The optimum hydrogenation reaction conditions are: reaction temperature 160℃, hydrogen partial pressure 0.8 MPa and reaction time 6 h. The activity stability of the Ni-Cu-B amorphous catalyst was also measured, and the catalyst deactivation mechanism was studied. The conversion and selectivity of the catalyst after being used for five times are 99.2% and 51.0%, respectively, which are not obviously decreased compared to fresh catalyst (conversion and selectivity are 100% and 52.9%, respectively). This result indicates that the amorphous Ni-Cu-B catalyst has good stability. The specific surface area and pore volume of the catalyst decrease after usage, and agglomeration was observed. However, the amorphous structure is maintained, which indicates that the slight decrease of catalyst activity is probably due to the coverage of active center of the catalyst.
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