血红细胞状氮掺杂多孔碳材料的制备及其氧还原催化性能的研究

摘要

A red-blood-cell-like nitrogen-doped porous carbon catalyst with a high nitrogen content (9.81％) and specific surface area (631.46 m2/g) was prepared by using melamine cyanuric acid and glucose as sacrificial template and carbon source, respectively. This catalyst has a comparable onset potential and a higher diffusion-limiting current density than the commercial 20 wt％ Pt/C catalyst in alkaline electrolyte. The oxygen reduction reaction mechanism catalyzed by this catalyst is mainly through a 4e pathway process. The excellent catalytic activity could origin from the synergistic effect of the in-situ doped nitrogen (up to 9.81％) and three-dimensional (3D) porous network structure with high specific surface area, which is conducive to the exposure of more active sites. It is interesting to note that the catalytic activity of oxygen reduction strongly depends on the proportion of graphic N rather than the total N content.%以三聚氰胺氰尿酸为氮源和自牺牲模板,葡萄糖为碳源,采用两步法制备了一种高氮含量(9.81％)和高比表面积(631.46 m2/g)的血红细胞状氮掺杂多孔碳材料.该催化剂在碱性电解液中的起始电位和极限电流密度均优于商用20 wt％Pt/C催化剂.该催化剂主要是通过四电子途径来催化氧还原反应过程.其优异的催化活性来源于原位掺杂的高含量氮与三维(3D)高比表面积多孔网络结构的协同作用,这有利于活性位点的暴露.有趣的是,氧还原的催化活性很大程度上取决于石墨氮的比例,而不是氮元素的总含量.