Mcore-Ptshell(M=Fe、Co、Ni)纳米粒子电催化氧还原的对比研究

纳米Pt具有较高的氧还原催化活性,但抗甲醇性不足,对直接甲醇燃料电池的性能产生影响。本文采用胶体模板法制备Mcore-Ptshell(M=Fe、Co、Ni)核壳型纳米粒子,用XRD和TEM表征纳米粒子的微观形貌和结构,动电位法和交流阻抗考察电催化活性和抗甲醇性。结果显示,Mcore-Ptshell纳米粒子的平均粒径约为10 nm,壳层厚度约为2~3 nm,3种催化材料的氧还原活性均高于碳载纳米Pt,抗甲醇性也有明显提高,其中Fecore,1-Ptshell,1/C的活性最高,峰电流密度达到0.5833 mA.cm-2,Cocore,1-Ptshell,1/C次之,Nicore,1-Ptshell,1/C最低;Fecore,1-Ptshell,1/C与Nicore,1-Ptshell,1/C的抗甲醇性相当,略好于Cocore,1-Ptshell,1/C。

Performance of Oxygen Electrocatalytic Reduction on M-Pt(M=Fe, Co, Ni) Nanocatalyst

Pt-nanoparticles have high performance for oxygen reduction reaction, but lower methanol-resistance which influences the capability of DMFC. The M_core-Pt_shell(M=Fe, Co, Ni) nanoparticles were prepared by redox-transmetalation method, and characterized by TEM, XPS and XRD. The catalytic activity and methanol-resistance of electro-catalysts were measured by potentiodynamic and AC impedance. The results show that the mean particle size of M_core-Pt_shell were about 10 nm of diameter with 2~3 nm of shell thickness. The catalytic activity of M_core,1-Pt_shell,1 for ORR was markedly enhanced in comparison with Pt-nanoparticles supported on carbon-black, and the activities order of M_core-Pt_shell is Fe_core,1-Pt_shell,1>Co_core,1-Pt_shell,1>Ni_core,1-Pt_shell,1. The peak current density of Fe_core,1-Pt_shell,1/C reached 0.583 3 mA·cm^-2 in 0.5 mol·L^-1 H₂SO₄+1.0 mol·L^-1 CH₃OH solution. The methanol-resistance of Fe_core,1-Pt_shell,1/C was similar with that of Ni_core,1-Pt_shell,1, and better than that of Co_core,1-Pt_shell,1.