sc7b01367_si_001.pdf (1.96 MB)
Confined-Space-Assisted Preparation of Fe3O4‑Nanoparticle-Modified Fe–N–C Catalysts Derived from a Covalent Organic Polymer for Oxygen Reduction
journal contribution
posted on 2017-07-30, 00:00 authored by Jianing Guo, Yuanhui Cheng, Zhonghua XiangIron–nitrogen–carbon
(Fe–N–C) has been
considered as one of the most promising nonprecious metal catalysts
for the oxygen reduction reaction (ORR) in fuel cells and metal–air
batteries. Herein, we prepare a highly active Fe3O4/Fe–N–C catalyst (named COP@K10-Fe-900), for
the ORR from a layered tetraphenylporphyrin-based (TPP-based) covalent
organic polymer (COP) grown in nanoconfined space as precursors, followed
by iron ion incorporation and a pyrolysis process. The nanoconfined
space, i.e., montmorillonite (K10) template, contributes to the unique
layered structure of designed precursors and enables Fe3O4 nanoparticles to disperse uniformly in the resulting
layered Fe–N–C catalyst. The nanoconfined space reduces
the iron-based particle size from ∼50–150 to ∼10
nm. An enhancement of 50 mV was obtained after using layer space confinement
for half-wave potential. Moreover, the half-wave potential of the
newly developed COP@K10-900 exceeds 20 mV as compared to the benchmark
Pt/C in alkaline media. Therefore, we believe that this work can provide
an important guideline for designing highly active M–N–C
catalysts that can be widely used in energy conversion and storage
devices.