高催化活性Pd-Co3O4/MWCNTs催化剂对甲醇氧化的电催化性能

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.

Highly Active Pd-Co3O4/MWCNTs Catalysts for Methanol Electrocatalytic Oxidation

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.