离子液体辅助合成AuPd纳米海绵及催化性能

在功能化离子液体氯化1-羟乙基-3-甲基咪唑(HEmim]Cl)辅助下, 在室温水溶液中一步快速合成了具有多孔海绵状结构的AuPd纳米材料. 通过场发射扫描电子显微镜(FESEM)、 透射电子显微镜(TEM)、 X射线能谱(EDX)和X射线衍射分析(XRD)等对该材料进行了表征. 结果表明, AuPd纳米海绵为合金结构, 由表面粗糙的纳米颗粒聚集熔接而成. 采用不同摩尔比(3∶1, 1∶1或1∶3)的前驱物HAuCl₄和Na₂PdCl₄均可制备出海绵状AuPd合金结构. 离子液体对AuPd纳米海绵状结构的形成起关键作用. 在对硝基苯酚还原反应中, 不同组成的AuPd纳米海绵均表现出比商用Pd/C催化剂更优异的性能. 其中, Au₁Pd₃纳米海绵具有最高的催化活性, 反应在98 s内即可完成, 反应速率常数为0.0143 s ^-1, 是商用Pd/C的2.3倍. 该方法也可用于制备其它双金属(如PdCu, PtCu等)和多金属纳米海绵.

Ionic Liquid-assisted Synthesis of AuPd Nanosponges and Their Catalytic Performance

With the assistance of a functionalized ionic liquid,1-hydroxyethyl-3-methylimidazolium chloride(HEmim]Cl),the porous sponge-like AuPd nanomaterials was quickly one-pot synthesized in aqueous solution at room temperature.Using field emission scanning electron microscopy(FESEM),transmission electron microscopy(TEM),X-ray energy spectroscopy(EDX)and X-ray diffraction(XRD),the structures and composition of as-prepared sponge-like AuPd nanomaterials were characterized and analyzed.The results show that the AuPd nanosponges have alloy structures and are formed via the aggregation and fusion of roughed nanoparticles.With different molar ratios of HAuCl4 and Na2PdCl4 precursors(3∶1,1∶1 or 1∶3),all the products prepared have sponge-like alloy structures.The ionic liquid plays an important role for the construction of AuPd sponge-like structures.Futhermore,all the as-obtained AuPd nanosponges exhibit excellent catalytic performance than commercial Pd/C in the reaction of p-nitrophenol reduction,in which the Au1Pd3 nanosponges have the highest catalytic activity.In the presence of Au1Pd3 nanosponges,the reaction can be finished within only 98 s and the reaction rate constant is calculated to be 0??0143 s-1,which is 2??3 times higher than commercial Pd/C.Yet,the current protocol can be used to grow and assemble other bi-metallic(such as PdCu and PtCu)and multi-metallic nanosponges.