通过无模板自组装法与自牺牲制孔方式相结合, 制备金属-氮(M-N)原位共掺杂的多孔碳球材料(M/N-CS, M=Cu、Fe或Ni)。该方法通过二苯碳酰二肼、金属离子与糠醛自组装形成聚合物球, 在碳化过程中球体中不稳定的含氮微区分解形成多孔结构, 同时原位形成具有高催化活性的M-NX活性位点。通过控制金属源和多重反应条件, 既能保证碳化阶段碳球结构的稳定, 又可实现材料的孔隙率、孔径及形貌的灵活变化。利用SEM、TEM、XRD、物理吸附及XPS测试分别对材料的结构和掺杂进行分析。所得材料用于电催化氧还原测试, 其中Fe/N-CS材料的催化反应初始电位和半波电位分别为0.91V和0.79V(vs.RHE), 并以4e-转移方式进行反应。同时, 催化材料表现出远高于商业Pt/C催化剂的稳定性与耐甲醇性。
A series of metal-nitrogen (M-N) co-doped porous carbon spheres (M/N-CS, M=Cu, Fe or Ni) were prepared by the template-free method of self-assembly combined with self-sacrificial pore-making approach.In this method, diphenylcarbazide, metal ions and furfural were cooperated to form polymer spheres, and the unstable nitrogenous micro-regions in the sphere decomposed and formed porous structure during the carbonization process, while the M-NX active sites with high catalytic activity were formed in situ.By controlling the metal source and multiple reaction conditions, the stability of the carbon sphere structure could be ensured at the carbonization stage, meanwhile, the porosity, pore size and morphology of the materials could be changed flexibly.The structure and doping of the materials were analyzed by SEM, TEM, XRD, physical adsorption and XPS, respectively.The obtained materials had excellent catalytic performance in oxygen reduction reaction.The onset potential and half-wave potential of Fe/N-CS was 0.91V and 0.79V (vs.RHE), respectively, and the electron transfer number was close to 4.Moreover, Fe/N-CS material showed higher stability and tolerance toward methanol than commercial Pt/C catalyst.
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基金资助
国家自然科学基金面上项目(21974057)
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