高分散钴氮共掺杂碳纳米纤维氧还原催化剂

摘要

Transition metal-nitrogen doped carbon-based catalysts have become promising alternatives to precious metal catalysts for the oxygen reduction reaction (ORR).Here,we report a nitrogen-doped carbon nanofiber electrocatalyst coordinated with highly dispersed cobalt atoms (Co-N/C) with a high specific surface area prepared by an electrospinning method.X-ray diffraction (XRD) and high-resolution transmission electron microscopy (HR-TEM) results confirmed that Co was highly dispersed within the prepared Co-N/C catalyst.X-ray photoelectron spectroscopy for N 1s spectra showed that the N species mainly existed in the forms of pyridinic N and graphitic N.This Co-N/C catalyst exhibited considerable ORR performance with onset and half-wave potentials at 0.92 and 0.80 V (relative to the reversible hydrogen electrode (RHE)),which are comparable to those of commercial Pt/C.With the prepared Co-N/C catalyst as the cathode,a Zn-air battery displayed an open-circuit potential of 1.54 V and a peak power density of 190 mW·cm-2 at 25 ℃,which suggest a promising application.%过渡金属氮掺杂碳基催化剂已成为替代铂基氧还原反应(ORR)电催化剂的理想选择.本文通过静电纺丝技术制备了高比表面、高度分散的钴原子配位氮掺杂的碳纳米纤维催化剂(Co-N/C).X射线衍射(XRD)和高分辨率透射电镜(HRTEM)结果证实Co元素高度分散于制备的Co-N/C催化剂中.X射线光电子能谱结果表明N元素主要以吡啶N和石墨N形式存在.该Co-N/C催化剂对ORR反应呈现出较高的电催化活性,其氧还原起始和半波电位分别为0.92 V和0.80 V(相对于标准氢电极),接近于商业化Pt/C催化剂的性能.以制备的Co-N/C催化剂作为阴极,25℃下锌空气燃料电池的开路电位1.54V、最大功率密度达到了190 mV·cm-2表明该催化剂具有良好的应用前景.