摘要
开发高效、廉价及可持续的非贵金属还原催化剂对燃料电池的商业化进程尤为重要。在众材料中,Fe-N-C材料研究最为广泛,被视为最有可能替代铂基材料的催化剂。然而,其氧还原催化性能还待提高。为增强活性,一种可行的方法是将一维碳纳米管和二维碳纳米片整合成具有三维结构的复合材料。因为此结构能提供足量的有效活性位点,且能促进质量和电荷的快速传输。对此,本课题组设计并开发了一种基于氯化钠辅助的方法用于原位制备三维Fe-N-C复合材料。其中,绿色可循环利用的氯化钠晶体既作为骨架均匀分散前驱物(葡萄糖分子、三聚氰胺以及铁盐),又作为模板辅助碳纳米管和碳纳米片的生成[1]。基于此方法获得的复合材料具有明显的三维结构、高的比表面积及多的Fe@C结构。基于上述优点,所制备三维Fe-N-C复合材料表现出优异的ORR催化活性;进一步研究发现该材料还表现出良好的稳定性和抗甲醇性能。
To promote the oxygen reduction reaction(ORR) on a non-noble-metal catalyst, integrating two-dimensional(2D) nanosheets and one-dimensional(1D) nanotubes in one catalyst is considered as one of desirable approaches since this hybrid architecture can host more useful active sites and enhance mass/electron transfer. Herein, we demonstrated a sodium chloride-assisted strategy for the in-situ synthesis of a three-dimensional(3D) hybrid of carbon nanosheets and nanotubes. The micrometer-scale sodium chloride(Na Cl) crystal acted as a recyclable skeleton to distribute the precursors on its surfaces, and favor the growth of CNT and the formation of carbon nanosheets. The obtained materials with well 3D structure has high specific surface areas and many Fe@C structures. Benefiting from these features, the developed hybrid exhibited a significantly enhanced electrocatalytic activity for ORR. They also shows high stability and methanol tolerance ability.
引文
[1]Zhang Y.;Hu J.-S.;Wei Z.D.and Wan L.-J.;et al.J Mater.Chem.A,doi:10.1039/C6TA01655C.