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在乙二醇和水混合溶剂中,采用硼氢化钠还原的方法制备了多壁碳纳米管(MWCNT)负载的Pd和Pd-Ag纳米颗粒催化剂;在碱性介质中,用循环伏安法测试了这些催化剂对乙醇、正丙醇和异丙醇的电氧化性能。结果表明,Pd和Pd-Ag纳米颗粒均匀地分散在MWCNT表面;Pd/MWCNT、Pd4Ag1/MWCNT、Pd2Ag1/MWCNT和Pd1Ag1/MWCNT催化剂上金属颗粒的平均粒径分别为7、4、7和11 nm。相比乙醇和异丙醇,所制备的催化剂对正丙醇的氧化表现出较大的电流密度。与Pd/MWCNT催化剂相比,双金属PdnAg1/MWCNT(n=4、2、1)催化剂,尤其是Pd4Ag1/MWCNT上的电流密度更大,表明Ag的加入提高了Pd催化剂对醇氧化的电化学活性,其原因是因为醇氧化过程所产生的中间体物种在双金属Pd-Ag/MWCNT催化剂上的吸附力有所减弱。
Multiwalled carbon nanotubes (MWCNT) supported Pd and Pd-Ag nanoparticle catalysts were prepared by reduction with sodium borohydride in a mixed solvent of ethylene glycol and water. In an alkaline medium, cyclic voltammetry Electrooxidation of these catalysts to ethanol, n-propanol and isopropanol. The results showed that Pd and Pd-Ag nanoparticles were uniformly dispersed on the surface of MWCNT. The average particle sizes of Pd / MWCNT, Pd4Ag1 / MWCNT, Pd2Ag1 / MWCNT and Pd1Ag1 / MWCNT catalysts were 7, 4, 7 and 11 nm . Compared with ethanol and isopropanol, the catalyst prepared showed a large current density for the oxidation of n-propanol. The current density of the bimetallic PdnAg1 / MWCNT (n = 4,2,1) catalyst, especially Pd4Ag1 / MWCNT, is larger than that of the Pd / MWCNT catalyst, indicating that the addition of Ag improves the electrochemical activity of the Pd catalyst for alcohol oxidation The reason for this is that the adsorption capacity of the intermediate species produced by alcohol oxidation on the bimetallic Pd-Ag / MWCNT catalyst is weakened.