Langmuir, Vol.34, No.17, 4952-4961, 2018
Templating Synthesis of Mesoporous Fe3C-Encapsulated Fe-N-Doped Carbon Hollow Nanospindles for Electrocatalysis
Developing cost-efficient alternatives to the noble metal catalysts toward oxygen reduction reaction (ORR) has attracted much attention, Herein, a kind of mesoporous hollow spindlelike Fe-N-C electrocatalysts with iron carbide nanoparticles encased in the N-doped graphitic layers has been synthesized by a novel "reactive hard template" strategy through the Fe3+-assisted polymerization of dopamine on the Fe2O3 cores and the following calcinations. The Fe2O3 nanospindles not only as the hard template guide the formation of well-defined shape and structure of the catalyst but also as the reactive template provide Fe reservoir to generate Fe3C nanoparticles in the catalyst during the thermochemical process. The superiority in accessible active sites of Fe-N-x species, Fe3C nanoparticles in graphenelike layers, and highly mesoporous hollow structure enables the catalysts to exhibit excellent ORR performances including high catalytic activity, outstanding long-term cycling stability, and good tolerance to methanol.