铜,硫掺杂对铁氮碳氧还原催化剂性能的提升作用

Enhancement of Performance of Fe-N-C Catalysts by Copper and Sulfur Doping for the Oxygen Reduction Reaction

采用FeCl3·6H2O,Cu(NO3)2·3H2O,KSCN,氧化BP-2000和三聚氰胺分别作为铁源、铜源、硫源、碳源和氮源,制备了一系列非贵金属氧还原电催化剂.通过透射电子显微镜、X射线粉末衍射、X射线光电子能谱和电感耦合等离子体原子发射光谱等表征了催化剂的形貌和结构,并通过旋转圆盘和旋转环盘测试研究了催化剂的性能,分析了铜,硫掺杂对于催化剂性能的提升作用.结果表明,与铜掺杂相比,硫掺杂能更大幅度地提高催化剂的周转率(TOF),并有效降低过氧化氢产率;同时铜,硫双掺杂的催化剂具有更高的TOF和更低的过氧化氢产率.

A series of nonnoble metal oxygen reduction electrocatalysts was prepared using FeCl3·6H2O,Cu(NO3)2·3H2O,KSCN,mildly oxidized BP-2000 and melamine as iron source,copper source,sulfur source,carbon source and nitrogen source,respectively.The morphology and structure of the catalysts were characterized by transmission electron microscopy( TEM),X-ray diffraction( XRD),X-ray photoelectron spectroscopy( XPS) and inductively coupled plasma atomic emission spectroscopy( ICP-AES).Then the oxygen reduction performances of the catalysts were evaluated by rotating disk and rotating disk ring tests,and the effect of copper and sulfur doping on catalysts performance was analyzed.The results demonstrate that sulfur doping can significantly promote turnover frequency( TOF) values of Fe-N-C catalysts than copper doping,and effectively reduce peroxide yields.In addition,the copper and sulfur doped Fe-N-C catalyst possesses higher TOF value and lower peroxide yield than the undoped Fe-N-C catalyst.The activation of Fe-Nx sites by sulfur doping and the synergistic effect of adjacent copper-based sites improve the activity and selectivity of the catalysts for oxygen reduction reaction.