Superior Fe _x N electrocatalyst derived from 1,1′-diacetylferrocene for oxygen reduction reaction in alkaline and acidic media

Abstract

Although Fe–N/C catalysts have received increasing attention in recent years for oxygen reduction reaction (ORR), it is still challenging to precisely control the active sites during the preparation. Herein, we report FexN@RGO catalysts with the size of 2–6 nm derived from the pyrolysis of graphene oxide and 1,1′-diacetylferrocene as C and Fe precursors under the NH3/Ar atmosphere as N source. The 1,1′-diacetylferrocene transforms to Fe3O4 at 600°C and transforms to Fe3N and Fe2N at 700°C and 800°C, respectively. The as-prepared FexN@RGO catalysts exhibited superior electrocatalytic activities in acidic and alkaline media compared with the commercial 10% Pt/C, in terms of electrochemical surface area, onset potential, half-wave potential, number of electrons transferred, kinetic current density, and exchange current density. In addition, the stability of FGN-8 also outperformed commercial 10% Pt/C after 10000 cycles, which demonstrates the as-prepared FexN@RGO as durable and active ORR catalysts in acidic media.

Fe‐N Doped Peanut Shell Activated Carbon as a Superior Electrocatalyst for Oxygen Reduction and Cathode Catalyst for Zinc‐Air Battery

“…Studies have shown that graphite N increased the limiting current density. [4,5,32,33] Combined with our electrochemical measurements result, The limit current density of the FePc/PSAC-3/1 is 5.5 mA cm À 2 , which is significantly higher than FePc (3.1 mA cm À 2 ). The increasing trend of graphite N's content is consistent with the increase of limiting current density, so such high level of graphitic nitrogen in FePc/PSAC-3/1 is considered to be responsible for the ideal ORR activity.…”

“…[1,2,29,30] We decomposed the high-resolution XPS N 1s spectra into four component peals at 398.6, 399.7, 401.2, 403.0 eV. The four peaks can be assigned to pyridinic N, pyrrolic N, graphitic N, and oxide N, respectively [3][4][5][6][31][32][33][34] (Figure 2c). The amount of pyridinic N in PSAC is 8.1 %, and there is almost no pyrrolic N in PSAC (Figure S4, Table S2).…”

“…In recent years, NNM catalysts, especially transition metal (e. g., Ni, Co, Fe, Cu) and nitrogen doped carbon (MeÀ NÀ C) have attracted tremendous research interest as a promising ORR electrocatalyst, they have been proved to replace Pt-based catalysts effectively. [4][5][6][7][8][9] Metallophthalocyanines (MPC) is typical macrocycle molecule in the NNM catalysts explored, which can be used to generate the metal-N 4 component and is considered as potential candidates to replace the Pt-based catalysts. [10,11] Unfortunately, the poor conductivity and stability of MPC limit its usefulness as ORR catalysts.…”

A Hybrid of the Fe4N–Fe Heterojunction Supported on N-Doped Carbon Nanobelts and Ketjen Black Carbon as a Robust High-Performance Electrocatalyst

“…Therein, the peaks at 711.1 and 717.1 eV can be ascribed to the Fe 2+ and Fe 3+ 2p 3/2 orbitals, respectively, of Fe–N species, while the peaks at 724.1 and 727.0 eV represent the Fe 2+ and Fe 3+ 2p 1/2 orbitals, respectively, of Fe species in the Fe–N configuration . The peak at 708.2 eV demonstrates the existence of zero-valence metallic Fe . The high-resolution N 1s XPS spectrum (Figure c) of Fe 4 N–Fe@N-C/N-KB demonstrates the coexistence of N atoms in five configurations, viz., pyridinic-N (398.5 eV), Fe–N (398.9 eV), pyrrolic-N (399.5 eV), graphitic-N (401.0 eV), and oxidized-N (402.6 eV) .…”

“…The Fe signal of Fe 4 N–Fe@N-C/N-KB (Figure b) can be fitted with five peaks. Therein, the peaks at 711.1 and 717.1 eV can be ascribed to the Fe 2+ and Fe 3+ 2p 3/2 orbitals, respectively, of Fe–N species, while the peaks at 724.1 and 727.0 eV represent the Fe 2+ and Fe 3+ 2p 1/2 orbitals, respectively, of Fe species in the Fe–N configuration . The peak at 708.2 eV demonstrates the existence of zero-valence metallic Fe .…”