Pt纳米颗粒在氮掺杂空心碳微球上的高分散负载及其氧还原性能

通过热解自聚合多巴胺法制备了氮掺杂空心碳微球(N-HCMS), 并采用微波辅助乙二醇还原方法把Pt纳米粒子负载于N-HCMS上制得了Pt/N-HCMS催化剂. 催化剂的表面形貌、晶体结构及其比表面积和孔径分布等分别采用扫描电子显微镜、透射电子显微镜、X射线衍射仪及比表面分析仪等进行表征. 采用循环伏安法和线性扫描伏安法研究了Pt/N-HCMS 催化剂在酸性条件下的电催化氧还原性能. Pt/N-HCMS 催化剂由于Pt纳米粒子的均匀分散、N-HCMS载体的快速电子传递及其独特的微孔和中空结构而具有很高的电催化氧还原活性, 其质量比活性是E-TEK Pt/C 催化剂的近两倍. Pt/N-HCMS 催化剂还具有优良的稳定性. 本工作对于开发高性能的燃料电池阴极催化剂具有重要意义.

Well-Dispersed Platinum Nanoparticles Supported on Nitrogen-Doped Hollow Carbon Microspheres for Oxygen-Reduction Reaction

Nitrogen-doped hollow carbon microspheres (N-HCMS) were synthesized by carbonization of poly(dopamine). Platinum (Pt) nanoparticles (NPs) were deposited onto the N-HCMS via a microwaveassisted reduction process. The morphology, surface area, and pore size distribution of the N-HCMS supported Pt catalysts (Pt/N-HCMS) were characterized by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, and surface area and porosimetry measurements. The electrocatalytic properties of the Pt/N-HCMS catalyst towards oxygen-reduction reaction were investigated by cyclic voltammetry and linear sweep voltammetry. The Pt/N-HCMS catalyst showed almost double the specific mass activity of a commercial carbon supported Pt catalyst. This was attributed to a uniform dispersion of the Pt NPs and the unique mesoporous and hollow structure of N-HCMS. In addition, fast electron transfer processes were found to occur on the nitrogen doped N-HCMS and the catalyst exhibited excellent long-term stability. This work is of significance for the development of high-performance cathodic catalysts in fuel cells.