纳米镍对硝基苯酚类物质的催化加氢性能研究

Study on catalytic hydrogenation of nitrophenol by nano nickel

通过水热合成法,以甘露醇为配体制备镍纳米材料。结构表征显示,该镍纳米材料具有较大的比表面积(126.9 m^(2)/g),且多个镍纳米粒子相互连接形成链状结构,多个链状的纳米颗粒进而又架构成多孔的三维网状结构。该纳米材料在对硝基苯酚(4-NP)的液相催化加氢反应中,其三维网状结构可以为4-NP加氢反应提供丰富而稳定的活性位点和快速的界面电子转移,进而有效加快反应速率。其表观反应速率常数(k_(app))达到0.796 min^(-1),是商业雷尼镍催化剂的6倍多。循环反应性能测试发现该催化剂在循环使用10次后仍保持81%的催化活性,说明该纳米镍催化剂具有比较突出的催化性能和较高的稳定性。此外,该纳米镍催化剂也显示出对其他硝基苯酚类物质及偶氮类染料较高的催化加氢活性,因而可将其用于环境中多种有机污染物的降解处理。这在环境保护、工业催化领域均具有一定的应用前景。

Approximately spherical nickel(Ni) nanoparticles were prepared by simple hydrothermal synthesis using polyhydroxy mannitol as ligand.A series of structural characterization results showed that the nickel nanoparticles had a large specific surface area(126.9 m^(2)/g),many of which joined together to form chain structures,and numerous chains then constructed porous three-dimensional network structures.The prepared Ni nanoparticles was applied in liquid phase catalytic hydrogenation of nitrophenol(4-NP) with outstanding catalytic performance.Its three-dimensional network structures can provide rich and stable active site and rapid interfacial electron transfer for 4-NP hydrogenation,thus effectively accelerating the reaction rate.The apparent reaction rate constant(k_(app)) reached 0.796 min^(-1),over 6 times higher than that of industrial Raney nickel catalyst.Cyclic reaction performance test results displayed that this nano-Ni catalyst maintained 81%of catalytic activity towards hydrogenation of nitrophenol after 10 cycles of use,indicating its high stability.In addition,the nano-Ni catalyst also exihibited high catalytic hydrogenation activity for other nitrophenol and azo dyes,which can be used for the degradation of a variety of organic pollutants in the environment.This endows it with potential applications in environmental protection and industrial catalysis.