高活性位点密度Fe-N共掺杂碳纳米片的制备及氧还原性能

从三聚氰胺和均苯四甲酸酐单体出发, 通过熔融盐法合成了三嗪结构聚酰亚胺纳米片, 借助类石墨相氮化碳(g-C₃N₄)与铁离子的配位作用, 经高温热处理形成了高效掺杂的Fe-N/C催化剂. 研究结果表明, 该催化剂为表面粗糙的纳米片结构, 比表面积高达1794 m²/g. 通过g-C₃N₄的引入和含量的调控, 催化剂中铁元素的掺杂量最高可达1.13%(摩尔分数), 为未引入g-C₃N₄的3.3倍, 其原因可归结于g-C₃N₄配位锚定了铁离子, 其较强的配位作用可以避免高温热处理时铁元素的迁移和聚集. 该催化剂在酸性条件下氧还原反应半波电位为0.79 V, 10000周加速测试后的半波电位衰减了30 mV, 表现出较好的氧还原活性.

Preparation and Oxygen Reduction Performance of Fe,N co-Doped arbon Nanoplate with High Density of Active Sites†

Fe, N co-doped carbon nanoplate catalyst with high active sites was developed via methods of polymerization of triazine polyimide and carbonization within melting salt of ZnCl₂/KCl with the aid of g-C₃N₄ to anchor Fe³⁺. The as-prepared NPT-C₃N₄-0.5 catalyst displays high specific surface area of 1794 m²/g. The iron atoms uniformly distribute in the carbon skeleton with an increased doping amount up to the molar percentage of 1.13%, 3.3 times of the one without g-C₃N₄, which can be attributed to the coordination between g-C₃N₄ and iron to decrease its aggregation under high temperature. The catalyst exhibits excellent catalytic activity for oxygen reduction reaction(ORR) in acid media. Typically, the half-wave potential(E_1/2) of the catalyst can reach up to 0.79 V(vs. RHE) and only decreases by 30 mV after 10000 potential cycles of accelerated durability test in acid media, showing high activity towards ORR.