June 19, 2019
Journal Article

Defect-Free Encapsulation of Fe0 in 2D Fused Organic Networks as a Durable Oxygen Reduction Electrocatalyst

Changmin Kim
Guntae Kim
Seok-Jin Kim
Javeed Mahmood
Seong-Wook Kim
James De Yoreo
Gao-Feng Han
Sun-Min Jung
Guomin Zhu
Jong-Beom Baek
ABSTRACT: Because they provide lower cost but comparable activity to precious platinum (Pt)-based catalysts, nonprecious iron (Fe)-based materials, such as Fe/Fe3C and Fe-N-C, have gained considerable attention as electrocatalysts for the oxygen reduction reaction (ORR). However, their practical application is hindered by their poor stability, which is attributed to the defective protection of extremely unstable Fe nanoparticles. Here, we introduce a synthesis strategy for a stable Fe-based electrocatalyst, which was realized by defect-free encapsulation of Fe nanoparticles using a two-dimensional (2D) phenazine-based fused aromatic porous organic network (Aza-PON). The resulting Fe@Aza-PON catalyst showed electrocatalytic activity (half-wave potential, 0.839V; Tafel slope, 60 mV decade-1) comparable to commercial Pt on activated carbon (Pt/C, 0.826 V and 90 mV decade-1). More importantly, the Fe@Aza-PON displayed outstanding stability (zero current loss even after 100 000 cycles) and tolerance against contamination (methanol and CO poisoning). In a hybrid Li-air battery test, the Fe@Aza-PON demonstrated performance superior to Pt/C.

Revised: June 19, 2019 | Published: February 7, 2018

Kim S., J. Mahmood, C. Kim, G. Han, S. Kim, S. Jung, and G. Zhu, et al. 2018. "Defect-Free Encapsulation of Fe0 in 2D Fused Organic Networks as a Durable Oxygen Reduction Electrocatalyst." Journal of the American Chemical Society 140, no. 5:1737-1742. PNNL-SA-133639. doi:10.1021/jacs.7b10663