A novel Fe–N–C catalyst for efficient oxygen reduction reaction based on polydopamine nanotubes

Abstract

One-dimensional Fe-N-codoped porous carbon materials have shown great potential as sustainable and efficient oxygen reduction reaction (ORR) catalysts. Herein, a highly active ORR 1D Fe-N-C catalyst has been developed by pyrolyzing a complex of polydopamine nanotubes and Fe(NO) at 800 °C. Porous PDA nanotubes as a resource for nitrogen-doped carbon and a coordination platform for Fe can provide well-distributed catalytic sites (Fe-N) after pyrolysis, and generate graphene-like carbon covers with proper thicknesses on Fe/FeC nanoparticles that effectively prevent agglomeration. Thanks to the 1D mesoporous morphology and hybrid composition, the rationally designed catalyst exhibits comparable ORR activity to the commercial Pt/C catalyst, and superior durability and methanol tolerance in alkaline media. Polydopamine nanotubes have demonstrated effects in the fabrication of efficient ORR catalysts which can be described as "killing three birds with one stone". The excellent electrocatalytic performance makes this novel 1D Fe-N-C catalyst a promising non-precious metal catalyst for practical fuel cell application.

One‐Pot Synthesis of a Highly Active 3‐Dimensional Fe−Nx−CNTs/rGO Composite Catalyst for Oxygen Reduction

“…Furthermore, the introduction of small N‐containing organics promoted the appearance of more N species than the macrocycles. Meanwhile, the contents of pyridinic N (44.8 %) and Fe‐N 4 (10.6 %) in our system are higher than those previous reports which is believed to greatly benefit the ORR activity . This discovery may provide a new method to adjust the N species and their content in Fe‐N−C catalysts.…”

“…[36] The surface components of Fe-N x -CNTs/rGO were characterized using XPS measurements (Figure 3c and Figure 3d). The XPS fitting of N 1s spectra ( Figure 3c [36,38,39] Different from our previously reported Fe-N x /CNTs/rGO using FePc as the precursor, [23] there were moreN-containing species that could be observed in the FeÀ N x À CNTs/rGO samples prepared by onepot synthesis.This difference mainly resulted from their different nitrogen sources, implying that the nitrogen precursor may have a vital role in the formation of N species. Furthermore, the introduction of small N-containing organics promoted the appearance of more N species than the macrocycles.…”

“…The surface components of Fe‐N x ‐CNTs/rGO were characterized using XPS measurements (Figure c and Figure d). The XPS fitting of N 1s spectra (Figure c) confirmed there were seven kinds of N species co‐existing in the final catalysts, corresponding toPyridinic N(398.4 eV), Fe−N 4 (399.4 eV), Pyrrolic N(400.1 eV), Quaternary N(401.1 eV), Graphitic N(401.8 eV),Pyridinic N−O(402.7 eV),and Oxidized N(403.5 eV) ,, there were moreN‐containing species that could be observed in the Fe−N x −CNTs/rGO samples prepared by one‐pot synthesis.This difference mainly resulted from their different nitrogen sources, implying that the nitrogen precursor may have a vital role in the formation of N species.…”

“…As a reference, the Fe foil shows a strong peak at ∼2.20 Å, corresponding to first shell back scattering, whereas the FePc sampleexhibits a strong peak located at ∼1.4 Å, indicating that one Fe atom is bound with four nitrogen atoms. Both of Fe−N x /CNTs/rGO (FePc) and Fe−N x −CNTs/rGO (one‐pot) have a discernible peak at ∼1.4 Å, implying the existence of Fe−N 4 species ,, . However, a recognizable peak located at ∼2.20 Å could still be captured in Fe−N x −CNTs/rGO (one‐pot).…”

Noble‐free oxygen reduction reaction catalyst supported on Sengon wood ( Paraserianthes falcataria L. ) derived reduced graphene oxide for fuel cell application

“…From above data, the Fe/Urea/RGO and Fe/ChoCl/RGO demonstrated analogous pore volume size despite the differences in the surface area. High pore volume was believed to accelerate the oxygen reactants to arrive at the active sites and, thus, giving high onset potentials and current densities . Pore distribution examined by BJH adsorption method ( Figure B ) depicted mesopores sized ~8 nm on Fe/Urea/RGO and ~3 nm on Fe/ChoCl/RGO.…”