Pt-NiO／SiO2纳米杂化体催化剂的制备及其催化合成对氨基苯酚的研究

摘要

PtNi bimetallic alloy nanopartilces with fcc crystal phase were synthesized by a liquid phase reduction method .The SiO2 supported PtNi bimetallic alloy nanopartilces was then used as precursor to obtain the Pt -NiO/SiO2 catalyst calcined at 500 ℃.Combined with XRD and TEM results ,it was found that the particle size of Pt-NiO/SiO2 using PtNi alloy nanoparticle precursor did not increase by calcination,indicating good thermal stability.The obtained catalysts were tested for catalytic reduction of p-Ni-trophenol to p-aminophenol in presence of sodium borohydride monitored by UV-visble.The results show that the catalytic activity and reaction rate of Pt-NiO/SiO2 catalyst was significantly higher than Pt/SiO2 catalyst prepared by the same conditions probably due to its strong Pt-NiO/SiO2 interaction.%采用液相还原法合成出具有面心立方结构的PtNi双金属合金纳米颗粒，将其负载到SiO2载体上，然后在500℃空气氛下预处理原位合成Pt-NiO/SiO2纳米杂化体催化剂。采用XRD和TEM对样品进行了表征，结果表明，Pt-NiO/SiO2催化剂中Pt颗粒尺寸在焙烧过程中未增长，具有良好的稳定性。采用紫外吸收可见光谱仪对Pt-NiO/SiO2纳米杂化体催化剂和Pt/SiO2催化剂催化硼氢化钠还原对硝基苯酚合成对氨基苯酚的过程进行追踪测试。结果表明，Pt-NiO/SiO2纳米杂化体催化剂的催化活性和反应速率远高于Pt/SiO2催化剂的活性，这可能归因于Pt-NiO/SiO2之间的强相互作用。