Oxygen Reduction Electrocatalysts Based on Coupled Iron Nitride Nanoparticles with Nitrogen-Doped Carbon

Abstract

Aimed at developing a highly active and stable non-precious metal electrocatalyst for oxygen reduction reaction (ORR), a novel Fe x N y /NC nanocomposite-that is composed of highly dispersed iron nitride nanoparticles supported on nitrogen-doped carbon (NC)-was prepared by pyrolyzing carbon black with an iron-containing precursor in an NH 3 atmosphere. The influence of the various synthetic parameters such as the Fe precursor, Fe content, pyrolysis temperature and pyrolysis time on ORR performance of the prepared iron nitride nanoparticles was investigated. The formed phases were determined by experimental and simulated X-ray diffraction (XRD) of numerous iron nitride species. We found that Fe 3 N phase creates superactive non-metallic catalytic sites for ORR that are more active than those of the constituents. The optimized Fe 3 N/NC nanocomposite exhibited excellent ORR activity and a direct four-electron pathway in alkaline solution. Furthermore, the hybrid material showed outstanding catalytic durability in alkaline electrolyte, even after 4,000 potential cycles.

Cost-Effective and Facile Preparation of Fe2O3 Nanoparticles Decorated N-Doped Mesoporous Carbon Materials: Transforming Mulberry Leaf into a Highly Active Electrocatalyst for Oxygen Reduction Reactions

“…In this respect, enormous viable noble-metal-free catalysts (Fe, Co, etc.) [6,7], or metal oxide [8], sulphide [9], nitride [10], carbide [11], metal-free carbon based materials [12] and nitrogen-doped carbon [13] have been actively pursued. Among above mentioned catalysts, the application of iron oxide as the electrocatalyst is…”

Medium Modulated Oxygen Reduction Activity of Fe/Co Active Centre‐engrafted Electrocatalysts

“…In the case of CoÀ N-GVC, the two less intense peaks appeared at the 2θ values of 44.4 and 51.6°are attributed to the CoN x phase (ICDD reference code: 00-041-0943). [30][31][32] Here, it should be noted that the carbide phase is formed in the system along with the grafting of the active center. [27] Similarly, in FeÀ N-GVC, the broad peaks at 43.8 and 44.8°represent the FeN x phase.…”

“…[28][29] In the XRD 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 pattern of Fe/2CoÀ N-GVC, two peaks lying closely at the 2θ values of 43.8 and 44.8°are observed; these peaks are assigned to the FeN x and CoN x phases which are expected since the composite contains both Fe and Co as the metal precursors during its synthesis. [30][31][32] Here, it should be noted that the carbide phase is formed in the system along with the grafting of the active center. [33] The carbon framework plays a crucial role in the modulation of the catalytic activity.…”

Effect of Catalyst Pore Size on the Performance of Non‐Precious Fe/N/C‐Based Electrocatalysts for High‐Temperature Polymer Electrolyte Membrane Fuel Cells

“…With regard to the elemental composition of the synthesized catalysts, the combined XPS and ICP analysis were performed for every catalyst tested (Table S2). It is found that proper use of Fe amounts in the catalysts is a critical factor affecting the efficiency and the selectivity of the ORR process and the optimal Fe contents for the highly active Fe/N/C catalysts are found to be less than 5 wt.% Fe ,,. Further, experimental Fourier transform at the Fe K‐edge obtained by fitting EXAFS data identified Fe−Fe, Fe−N and Fe−O bond in the prepared Fe/N/C composites (Figure S7).…”