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采用硼氢化钠一步还原法,首先得到PdAg和PdAu双金属合金纳米颗粒。利用XRD、TEM以及紫外可见光光谱技术对其进行了表征分析。结果表明,PdAg和PdAu两种合金都具有纳米颗粒分散均匀且颗粒尺寸小等优点。随后采用胶体沉积法将两种合金均匀地负载到Al_2O_3上,成功获得PdAg/Al_2O_3和PdAu/Al_2O_3两种金属纳米催化剂。在邻氯硝基苯加氢反应中,与Pd/Al_2O_3纳米催化剂相比,PdAg/Al_2O_3催化剂显示出95.5%的选择性,而PdAu/Al_2O_3催化剂的选择性高达98.7%,这可能归因于Pd与Ag或Au金属间的协同效应。
Using sodium borohydride one-step reduction method, the first PdAg and PdAu bimetallic alloy nanoparticles. The XRD, TEM and UV-visible spectroscopy techniques were used to characterize the results. The results show that PdAg and PdAu both have the advantages of uniform dispersion of nano-particles and small particle size. Subsequently, two kinds of metal nanocatalysts, PdAg / Al_2O_3 and PdAu / Al_2O_3, were successfully obtained by colloidal deposition on the Al_2O_3. In the o-chloronitrobenzene hydrogenation reaction, the PdAg / Al 2 O 3 catalyst shows a 95.5% selectivity compared to the Pd / Al 2 O 3 nano catalyst, while the selectivity of the PdAu / Al 2 O 3 catalyst is as high as 98.7%, which may be attributed to Pd Synergistic effect with Ag or Au metal.