氮掺杂还原氧化石墨包覆金属钴复合材料的制备及其氧还原性能的研究

采用搅拌反应法制备了ZnCo（ZIF）与氧化石墨（graphite oxide，GO）的复合材料，热处理得到Co@N-doped rGO催化剂。通过X射线衍射（X-ray diffraction，XRD）和扫描电子显微镜（scanning electron microscopy，SEM）对催化剂进行结构表征，通过X射线光电子能谱（X-ray photoelectron spectroscopy，XPS）对催化剂进行表面元素分析，分别考察了金属（Zn和Co）加入量和热处理温度对催化剂氧气还原反应（oxygen reduction reaction，ORR）催化性能的影响，结果表明：所制备的催化剂整体呈层状分布，表面附着金属小颗粒团簇；随着金属加入量的增加，催化剂的ORR催化性能先增强后减弱；随着热处理温度的升高，催化剂的ORR催化性能先增强后减弱。所制备的S-2-850催化剂具有最好的ORR催化性能，在0.1 mol/L KOH电解液中，其起始电位和半波电位分别为0.871 V和0.804 V，在相同测试条件下活性稳定性优于20% Pt/C。

Preparation of nitrogen-doped reduced graphite oxide coated metal cobalt composites as electrocatalysts for oxygen reduction

A series of composite of ZIF(ZnCo) and graphite oxide (GO) have been synthesized by using a mixing method, and the materials used as precursors to synthesize Co@N-doped rGO catalysts at high temperatures. The catalysts were characterized by X-ray diffraction (XRD)and scanning electron microscopy (SEM), while X-ray photoelectron spectroscopy (XPS) was used to investigate the surface elements. The effects of varying the Zn and Co composition and the thermolysis temperature on the performance of the catalysts in the oxygen reduction reaction (ORR) were investigated. The results show that the catalyst is distributed in a layered manner with small metal clusters attached on the surface. The oxygen reduction performance of the catalyst initially increased and then decreased as the amount of metal (Zn and Co) was increased, and increased as the thermolysis temperature was increased. The ORR activity of the optimal catalyst had onset and half-wave potentials of 0.871 V and 0.804 V, respectively, in 0.1 mol/L KOH electrolyte. The activity stability was better than that of 20% Pt/C under the same test conditions.