Three-dimensional Fe-N-C aerogel catalysts for the oxygen reduction reaction (ORR) are prepared with resorcinol–formaldehyde–melamine and iron precursor using one-pot sol-gel process followed by supercritical drying and heat treatment in nitrogen (N₂) and then ammonia (NH₃) atmospheres. We studied the effect of the synthesis conditions (Fe precursor and Fe content) of organic aerogel and the heat treatment parameters (including temperature and duration) under N₂/NH₃ atmosphere on the structural properties and ORR catalytic activities of the resulting Fe-N-C aerogel catalysts. The Fe-N-C aerogel catalysts were characterized by X-ray diffraction, scanning electron microscopy, X-ray photoelectron spectroscopy, and N₂-adsorption/desorption, and the ORR activities were studied by the rotating disk electrode method. It was found that the pore structure, the chemical composition, and ultimately the ORR performance were largely affected by the nature of iron precursor, iron content, and the conditions of heat treatment. The catalysts using Iron (III) acetylacetonate as Fe precursor incorporated with 3 wt% of Fe followed by the HT at 800 °C for 1 h under N₂ and then 950 °C under NH₃ for 30 min showed the highest content of active site (Fe-N_x) and largest mesopore volume, resulting in an enhanced catalytic activity and mass-transport property.

采用一锅溶胶-凝胶法，用间苯二酚-甲醛-三聚氰胺和铁前驱体制备用于还原反应的三维Fe-NC气凝胶催化剂，然后超临界干燥并在氮气（N ₂）中进行热处理氨（NH ₃）气氛。我们研究了有机气凝胶的合成条件（Fe前驱体和Fe含量）以及N ₂ / NH ₃气氛下的热处理参数（包括温度和持续时间）对所得Fe-NC的结构性能和ORR催化活性的影响气凝胶催化剂。Fe-NC气凝胶催化剂通过X射线衍射，扫描电子显微镜，X射线光电子能谱和N ₂表征。旋转圆盘电极法研究了吸附-解吸和ORR活性。发现孔结构，化学组成以及最终的ORR性能在很大程度上受铁前体的性质，铁含量和热处理条件的影响。使用乙酰丙酮铁（III）作为铁前体的催化剂，先加入3 wt％的Fe，然后在N ₂下于800°C的HT下进行HT 1小时，然后在NH _3下于950°C的HT下进行30分钟，显示出最高的活性位点（Fe-N _x）和最大的中孔体积，导致增强的催化活性和传质性能。