中文摘要：

采用改进的电化学三步法制备铂钌／多壁碳纳米管（PtRu／MWCNTs）和铂钌镍／多壁碳纳米管（FtRuNi／MWCNTs）金属纳米复合材料，用透射电子显微镜、能量色散光谱、X射线多晶衍射和x光电子能谱对其形貌、成分和结构进行表征和分析．采用循环伏安法和计时电流法研究PtRu／MWCNTs和PtRuNi／MWCNTs金属纳米复合材料对O还原（ORR）和甲醇氧化的电催化活性和稳定性．结果表明，PtRuNi／MWCNTs的0RR起始电位发生明显正移，峰电流增高，甲醇氧化峰电流高，氧化峰电位负移，具有高抗CO中毒性能且稳定性好，是良好的直接甲醇氧化燃料电池阳极催化剂候选材料．同时，PtRuNi／MWCNTs的高ORR和甲醇氧化电催化活性，是双功能工作理论、特殊三维结构和MWCNTs表面经电化学活化处理生成含O官能团多种因素的共同作用结果．

英文摘要：

PtRu catalyst has long application history in electrochemical field due to the wide prospect in direct methanol fuel cells （DMFCs）, but its performance remains to be improved further. There are usually two ways to enhance the catalytic activity of PtRu bimetallic catalyst. One is to add the third metal into alloy; the other is to improve the properties of carbon support. In this work, PtRu and PtRuNi nanoparticle clusters were electrochemically deposited on multi-walled carbon nanotubes （MWCNTs） through a three-step process, including an electrochemical treatment of MWC- NTs, electro oxidation of metal chloride to high valence of metal complex and an electro-conversion of PtRu and PtRuNi nanoparticle clusters on MWCNTs. The structure and elemental composition of the PtRu/MWCNTs and PtRuNi/MWCNTs electrodes were characterized by transmission electron mi- croscopy （TEM）, energy dispersive X-ray spectroscopy （EDX）, X-ray polycrystalline diffraction （XRD） and X ray photoelectron spectroscopy （XPS）. The electrocatalytic properties of the PtRu/MWCNTs and PtRuNi/MWCNTs electrodes for oxygen reduction reaction （ORR） and methanol oxidation wereinvestigated by cycle voltammetry （CV） method and current-time （CT） method. The results showed that PtRuNi/MWCNTs electrode exhibited a high If/Ib （the forward anodic peak/the reverse anodic peak current） value and an appreciably improved resistance to carbon monoxide （CO） poisoning in methanol solution, so a beneficial effect on the oxygen adsorption in dilute sulphuric acid solution was observed. The high electrocatalytic activity and good stability of PtRuNi/MWCNTs was attributed to the synergetic effect of bifunctional catalysis, three dimension structure and oxygen functional groups which generated after electrochemical activation treatment on MWCNTs surface. The successful preparation of PtRu/MWCNTs and PtRuNi/MWCNTs nanocomposites opens a new path for efficient dispersion of promising electrocatalysts in DMFCs.