一锅法制备磁性Ni-Ag纳米合金催化剂及其催化还原对硝基苯酚

One-pot Synthesis of Magnetic Ni-Ag Nano-Alloy Catalyst and Its Application in Reduction of 4-Nitrophenol

采用液相共还原一锅法制备了不同[Ni]∶[Ag]比例的磁性Ni-Ag纳米合金催化剂。利用XRD、SEM、TEM表征了催化剂的物相和形貌,利用XPS测试了催化剂表面元素价态,采用SQUID分析了催化剂的磁学性能;以对硝基苯酚的催化还原反应作为模型反应,研究了[Ni]∶[Ag]比例对磁性Ni-Ag纳米合金催化剂催化性能的影响,并考察了其循环使用性能。结果表明,磁性Ni-Ag纳米合金催化剂由直径50 nm左右的Ni-Ag合金颗粒组成,催化还原对硝基苯酚的催化活性随Ag含量的增加先增强后减弱,[Ni]∶[Ag]=1∶1的催化剂催化性能最好。该Ni-Ag纳米合金催化剂的饱和磁化强度为15.43 emu·g^(-1),具有很好的磁学性能,可实现磁回收和循环利用,循环使用5次后依然保持高催化活性和稳定性。

We prepared magnetic Ni-Ag nano-alloy catalysts with different ratios of [Ni]∶[Ag] by a one-pot liquid co-reduction method.Furthermore,we characterized the phase and morphology of the catalysts by XRD,SEM,and TEM,measured the valence state of the surface element of the catalysts by XPS,and analyzed the magnetic property by SQUID.Moreover,using the catalytic reduction of 4-nitrophenol as a model reaction,we studied the effects of the ratio of [Ni]∶[Ag] on the catalytic performance of Ni-Ag nano-alloy catalysts,and investigated the recycling performance.The results show that Ni-Ag nano-alloy catalyst consists of particles with a diameter of about 50 nm,and the catalytic activity firstly increases and then decreases with the increase of Ag content.Therein,the catalytic performance of catalyst with [Ni]∶[Ag]=1∶1 is the best.The saturation magnetization of the Ni-Ag nano-alloy catalyst is 15.43 emu·g^-1,which has good magnetic property and can be magnetically recyclable for reuse.After 5 times reuse,the nano-alloy catalyst still has high catalytic activity and stability.