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通过溶剂分散热处理方法制备了一种吡咯和对甲苯磺酸(TsOH)共同修饰的碳载非贵金属复合催化剂(Fe-N/C-TsOH),并采用扫描电子显微镜(SEM)、X射线衍射(XRD)和X射线光电子能谱(XPS)对催化剂的形貌和组成成分进行表征.借助循环伏安法(CV)和旋转圆盘技术研究了TsOH对催化剂在0.1 mol·L-1KOH介质中催化氧还原性能的影响.结果表明:TsOH的存在对催化剂催化氧还原反应(ORR)的活性影响很大.以其制备的气体扩散电极在碱性电解质溶液中催化氧还原过程时转移的电子数为3.899,远比不含TsOH修饰的催化剂催化氧还原的电子数(3.098)高.此外,研究发现600°C热处理过的Fe-N/C-TsOH催化剂表现出最佳的氧还原催化性能.相比未经热处理过的Fe-N/C-TsOH催化剂,起峰电位和-1.5 mA·cm-2电流密度对应的电压分别向正方向移动30和170 mV.XPS研究结果表明吡咯氮是催化剂主要活性中心,提供氧还原活性位,而TsOH加入形成的C―Sn―C和―SOn―有利于催化剂催化氧还原活性的提高,从而使该催化剂对氧还原表现出很好的电催化性能和选择性.
A novel Fe-N / C-TsOH catalyst was prepared by solvent-dispersion heat treatment. The catalysts were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) were used to characterize the morphology and composition of the catalyst.The catalytic effect of TsOH on the catalyst in 0.1 mol·L-1 KOH was studied by cyclic voltammetry (CV) Oxygen reduction performance.The results show that the presence of TsOH greatly affects the catalytic activity of the oxygen reduction reaction (ORR). The gas diffusion electrode prepared in the alkaline electrolyte solution catalyzed oxygen reduction process is 3.899, which is much higher than the number of electrons catalyzed by oxygen-free reduction (3.098) without TsOH modification.In addition, it was found that the Fe-N / C-TsOH catalyst treated at 600 ° C showed the best oxygen reduction catalytic performance. The voltages corresponding to the peak potentials and current densities of -1.5 mA · cm-2 moved 30 and 170 mV forward, respectively, compared to the untreated Fe-N / C-TsOH catalyst.XPS results showed that pyrrole nitrogen was the main catalyst Active center, providing oxygen reduction active site, Add TsOH formed C-Sn-C and -SOn- facilitate improved catalyst activity to catalyze oxygen reduction, so that the oxygen reduction catalyst exhibits good electrical properties and catalytic selectivity.