直接甲醇燃料电池用Co-N-C电催化剂的制备及性能

摘要

以三聚氰胺甲醛树脂和硝酸钴为前驱体,在Ar保护下采用高温碳化方法制备用于直接甲醇燃料电池( DMFC)阴极的含氮碳载钴(Co-N-C)氧还原电催化剂.利用热重与红外光谱联用、X射线衍射分析、元素分析等方法表征了催化剂的制备过程和结构,采用旋转圆盘电极测试考察了不同碳化温度对Co-N-C电催化剂氧还原催化活性的影响及电催化剂的耐醇性能,并采用该催化剂为阴极催化剂进行DMFC单电池测试.结果表明:Co-N-C电催化剂具有较高的电催化活性和较好的耐醇性能；其氧还原起始电位在0.5 V(vs.SCE)左右；700℃碳化温度下制备的Co-N-C电催化剂具有最高的氧还原催化活性.%Co-N-C oxygen reduction electro-catalysts for the cathode of the direct methanol fuel cell (DMFC) were first prepared via the pyrolysis in Ar atmosphere, with melamine formaldehyde resin and cobalt nitrate as the precursors. Then, the preparation and structure of the electro-catalysts were investigated by means of TG-FTIR, XRD and element analysis, and the electro-catalytic activity for oxygen reduction reaction as well as the methanol tolerance of the electro-catalysts was detected by using a rotating disk electrode. Finally, a DMFC single-cell test was carried out by using the prepared electro-catalysts as the cathode catalysts. The results indicate that Co-N-C electro-catalysts are of high electro-catalytic activity and strong methanol tolerance, and that the onset potential of the electro-catalysts for oxygen reduction is about 0.5 V (vs. SCE). Moreover, it is found that the catalyst prepared at 7001 possesses the highest electro-catalytic activity for oxygen reduction reaction.