中文摘要：

以Co（NO3）3·6H2O为钴源,聚乙二醇（PEG）20000为表面活性剂,与多壁碳纳米管（MWCNTs）混合后通过水热氧化法成功地合成了表面均匀分布纳米絮状Co3O4的MWCNTs复合物,进一步还原Pd的前驱体而制备得到Pd-Co3O4/MWCNTs复合催化剂.利用扫描电镜（SEM）、透射电镜（TEM）及X射线粉末衍射（XRD）等手段对样品的形貌和晶型结构进行了表征,结果表明Pd纳米粒子为面心立方晶体结构,均匀地分布在Co3O4修饰的MWCNTs表面.用循环伏安法和计时电流法表征结果表明：催化剂Pd-Co3O4/MWCNTs具有较大的电化学活性表面积,在碱性介质中对甲醇氧化具有更高的电催化活性和稳定性.研究结果表明,过渡金属氧化物纳米Co3O4颗粒在提高直接甲醇燃料电池（DMFC）催化性能研究中具有十分重要的作用,是一类很有潜力的载体催化剂.

英文摘要：

Nano-flocculent-Co3O4 modified multi-walled carbon nanotubes supported Pd nanoparticles （Pd-Co3O4 /MWCNTs）with uniform dimensions were prepared by a facile hydrothermal method using Co（NO3）3·6H2O as the cobalt source,polyethylene glycol（PEG）20000 as a surface active agent,and H2PdCl4 as the Pd precursor.The catalysts were characterized by scanning electron microscopy, transmission electron microscopy,and X-ray powder diffraction.The Pd nanoparticles had a face-centered cubic crystal structure and were well dispersed on the external walls of the Co3O4 /MWCNTs.The catalytic activity was studied by cyclic voltammetry and chronoamperometry toward methanol oxidation.The Pd-Co3O4 /MWCNT catalysts had a large electrochemically active area,good electrocatalytic performance, and stability toward methanol oxidation in alkaline media.All the results suggest that Co3O4 will improve the electrocatalytic activity in direct methanol fuel cells.