合成了四甲氧基苯基钴卟啉(CoTMPP)和四甲氧基苯基铁卟啉(FeTMPP)配合物,分别负载于经过双氧水和硝酸预处理且掺杂了MnOx的炭载体,用于质子交换膜燃料电池阴极氧还原反应电催化剂.讨论了不同中心金属离子、不同载体、不同预处理方法和不同焙烧温度对催化剂催化活性的影响.通过旋转圆盘电极技术(RDE)和紫外可见光谱(UV—vis)测试,利用循环伏安曲线(CV)和Koutevky-Levich关系式评价了电催化剂对氧还原反应的电催化性能.研究表明,CoTMPP负载于双氧水处理过的炭载体BP2000上活性最好,焙烧的最佳温度是900℃,同时发现在载体中掺杂MnOx并没有达到预期效果.
To obtain cathode electrocatalysts for the oxygen reduction in proton exchange membrane (PEM) fuel cell, iron and cobalt tetramethoxyphenylporphyrins adsorbed on pretreated carbons, including black pearls 2000 (BP) and Vulcan XC-72 (Vulcan) respectively by depositing MnOx were investigated in detail The effects of different central metal ions, carbon supports, pretreatment methods and various heat-treatment temperatures were compared. The catalysts were evaluated by RDE in 0.5 mol·L^-1 H2SO4. The best results were obtained for CoTMPP on BP pretreated by H2O2. The most active and stable catalysts were obtained by calcining at a high temperature (900℃). After heat treatment at 900℃, Co N4 bond structure in CoTMPP catalyst was no longer detected which meant that the central structure of the catalyst was changed during heat-treatment. Trying to deposit MnOx in carbons did not achieve the expected result in acid medium.