Abstract The development of highly active metal-free electrocatalysts with durability in both alkaline and acidic media as alternatives for platinum-based catalysts is critical for fuel cells and metal-air batteries. Herein, N-doped carbon nanofibers aerogels derived from commercial aramid are prepared using a facile and cost-effective process based on solvent-exchange followed by freeze-drying and pyrolysis under N2 atmosphere. The as-prepared catalyst exhibits high electrocatalytic activity towards the oxygen reduction reaction with a half-wave potential estimated to 0.91 V (vs. reversible hydrogen electrode) in 0.1 M KOH. This value is more positive than that of Pt/C. The N-doped carbon nanofibers aerogels also display excellent activity in 0.1 M HClO4, with only 83 mV difference in half-wave potential from that of Pt/C. In addition, the catalyst shows higher long-term durability and methanol-resistance than commercial Pt/C catalyst in both alkaline and acidic media. The efficient properties of N-doped carbon nanofibers aerogels are attributed to the synergistic effect of the hierarchical porous structure, defects and homogeneous distribution of abundant N species as electrocatalytic active sites in the carbon matrix. Overall, the good electrocatalytic performance combining with the simple cost-effective strategy make it a promising potential electrocatalyst for future use in fuel cells and metal-air batteries.

中文翻译：

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芳纶衍生的 N 掺杂碳纳米纤维气凝胶作为碱性和酸性介质中氧还原反应的有效电催化剂

摘要 开发在碱性和酸性介质中均具有耐久性的高活性无金属电催化剂作为铂基催化剂的替代品，对于燃料电池和金属-空气电池至关重要。在此，从商业芳纶衍生的 N 掺杂碳纳米纤维气凝胶是使用基于溶剂交换的简便且具有成本效益的方法制备的，然后在 N2 气氛下冷冻干燥和热解。所制备的催化剂对氧还原反应表现出高电催化活性，在 0.1 M KOH 中的半波电位估计为 0.91 V（相对于可逆氢电极）。该值比 Pt/C 的值更正。N 掺杂的碳纳米纤维气凝胶在 0.1 M HClO4 中也显示出优异的活性，与 Pt/C 的半波电位仅相差 83 mV。此外，该催化剂在碱性和酸性介质中均表现出比商业 Pt/C 催化剂更高的长期耐久性和耐甲醇性。N掺杂碳纳米纤维气凝胶的高效性能归因于分层多孔结构、缺陷和丰富的N物种作为碳基质中电催化活性位点的均匀分布的协同作用。总体而言，良好的电催化性能与简单的成本效益策略相结合，使其成为未来用于燃料电池和金属-空气电池的有潜力的电催化剂。缺陷和丰富的 N 物种作为碳基质中的电催化活性位点的均匀分布。总体而言，良好的电催化性能与简单的成本效益策略相结合，使其成为未来用于燃料电池和金属-空气电池的有潜力的电催化剂。缺陷和丰富的 N 物种作为碳基质中的电催化活性位点的均匀分布。总体而言，良好的电催化性能与简单的成本效益策略相结合，使其成为未来用于燃料电池和金属-空气电池的有潜力的电催化剂。