非晶态合金催化剂NiB、NiB/TiO_2的制备、表征及其环丁烯砜加氢催化活性的研究

Preparation, Characterization and Catalytic Behavior of the NiB and NiB/TiO_2 Amorphous Catalysts

分别采用化学还原法和浸渍还原法制备了系列NiB及NiB/TiO2非晶态合金催化剂,用XRD、ICP、SEM、SAED和DSC等技术对催化剂的物性进行了表征,并将其用于环丁烯砜加氢反应.研究了制备条件(镍硼摩尔比、滴加方式和金属离子浓度)对非晶态合金催化剂加氢活性的影响.结果表明,选择镍硼摩尔比为1∶2,Ni2+浓度为0.1mol/L,采用正滴加方式(将KBH4溶液滴加到Ni(NO3)2溶液中)所制得的NiB非晶态合金催化剂环丁烯砜加氢活性优于RaneyNi催化剂.对于NiB/TiO2负载型非晶态合金催化剂,镍的实际负载量达14.5%时,NiB/TiO2与NiB的环丁烯砜加氢催化活性相当.

A series of amorphous NiB and NiB/TiO_2 catalysts were prepared by the chemical reduction method and impregnation- reduction method, respectively. These catalysts were characterized by XRD, ICP, TEM, SAED and DSC. Their catalytic activities were measured through liquid phase hydrogenation of sulfolene under moderate pressure. Several preparation parameters such as the mole ratio of Ni^(2+)/BH_4^-, feeding method and concentration of the Ni^(2+) were investigated. The results showed that the NiB catalyst prepared by dropping KBH_4 solution to 0.1 mol/L Ni(NO_3)_2 aqueous solution with the mole ratio of Ni^(2+)/BH_4^- being 1∶2 had higher hydrogenation activity than Raney Ni. When the Ni loading of NiB/TiO_2 was 14.5%, the activity of this supported amorphous alloy catalyst could reach the activity of the unsupported NiB amorphous alloy catalyst. The thermal stability of the amorphous NiB alloy was increased owing to the introduction of the support.