Activity In Acidic Media Research Articles

Hexamine-Coordination-Framework-Derived Co–N-doped Carbon Nanosheets for Robust Oxygen Reduction Reaction

In this work, Co–N-doped carbon nanosheet (Co-NCS), obtained through a self-assembly strategy and subsequent pyrolysis process, was reported as an efficient ORR catalyst. Combining the unique 2D architecture and high N-doping level, the optimized Co-NCS exhibits a superior ORR performance with more positive onset potential (0.96 V) and half-wave potential (0.93 V) than those of commercial Pt/C under alkaline conditions. Additionally, the optimized catalyst also displays desirable ORR activity in acidic media, approaching that of commercial Pt/C. Significantly, the synergistic catalysis is demonstrated through selective etching of active species, holding great potential in an in-depth understanding of the contributions of CoNₓ and Co@C NPs in catalysts. Furthermore, the zinc–air batteries assembled with the optimized Co-NCS as the air cathode outperform the Pt-based zinc–air batteries. This finding sheds light on the synthesis of ORR catalysts and the exploration of their application in energy conversion systems.

Oxygen Evolution Reaction on Tin Oxides Supported Iridium Catalysts: Do We Need Dopants?

AbstractApplication of oxide supports is considered as a viable approach to decrease iridium loading in oxygen evolution reaction catalysis in acid electrolyte. While the most of the promising oxides are poor conductors, the need for doping is typically taken as granted, and a representative example is tin dioxide. There are still, however, serious concerns on the feasibility of this approach as we lack consensus on any activity gain by using such oxides, while doubts on stability are numerous. In this work, a set of catalyst/support combinations including two catalysts, viz. hydrous (IrOx) and rutile (IrO2) iridium oxides, and four supports, viz. SnO2 and Sb‐ (ATO), F‐ (FTO), and In‐doped (ITO) SnO2, are synthesized and characterized by a selection of complementary experimental techniques including rotating disk electrode and on‐line inductively coupled plasma mass spectrometry. It is found that the electrochemical activity in acid media of supported Ir catalysts is essentially the same, independent on presence or absence of dopants. Sb and In dopants are shown to be unstable and cause an increased dissolution of Sn. Besides, the degradation of the doped supports results in destabilization of iridium oxides. These results raise doubts on the real need for the use of dopants in SnO2‐based catalyst supports for electrochemical water splitting.

Iridium Oxide Catalyst Supported on Antimony-Doped Tin Oxide for High Oxygen Evolution Reaction Activity in Acidic Media

Lowering of the oxygen evolution reaction (OER) noble metal catalyst loading on the anode of a polymer electrolyte membrane water electrolysis (PEMWE) is a necessity for enabling the large-scale hy...

High-performance hydrogen evolution electrocatalysis using proton-intercalated TiO2 nanotube arrays as interactive supports for Ir nanoparticles

Surface-disordered, protonated TiO2 nanotube array substrates induce spontaneous deposition of metallic Ir nanoparticles and actively promote their electrocatalytic behavior for achieving remarkable hydrogen evolution activity in acidic media.

Heterostructured MoS2@Bi2Se3 nanoflowers: A highly efficient electrocatalyst for hydrogen evolution

The transition metal dichalcogenide MoS2 shows good catalytic properties for the hydrogen evolution reaction (HER). However, the HER activity of 2D MoS2 is limited by its poor electrical conductivity. Bi2Se3 nanosheets are topological insulators possessing metallic surface states, thereby displaying unconventional electron dynamics and excellent conductivity. Therefore, combining Bi2Se3 nanosheets and with MoS2 nanosheets represents a rational approach for improving the HER activity of MoS2. In this work, Bi2Se3 nanoflowers were first synthesized via a hot injection method, followed by the slow growth of MoS2 nanosheets on their surface to form heterostructured MoS2@Bi2Se3 nanoflowers. Compared to pristine Bi2Se3 and MoS2, the MoS2@Bi2Se3 nanoflowers exhibited outstanding HER activity in acidic media with an onset overpotential of 134 mV, an overpotential of 208 mV at 10 mA/cm2, a Tafel slope of 57 mV/dec and remarkable stability. The enhanced HER catalytic activity offered by the MoS2@Bi2Se3 nanoflowers is attributed excellent electron transfer from Bi2Se3 to MoS2, as well as the abundance of edge-rich MoS2 nanosheets vertically aligned on the Bi2Se3 support that act as H2 evolution sites.

Effect of Ni Doping on the MoS2 Structure and Its Hydrogen Evolution Activity in Acid and Alkaline Electrolytes

We have investigated three-dimensional (3D) MoS2 nanoarchitectures doped with different amount of Ni to boost the hydrogen evolution reaction (HER) in alkaline environment, where this reaction is normally hindered. As a comparison, the activity in acidic media was also investigated to determine and compare the role of the Ni sites in both media. The doping of MoS2, especially at high loadings, can modify its structural and/or electronic properties, which can also affect the HER activity. The structural and electronic properties of the Ni doped 3D-MoS2 nanoarchitecture were studied by X-ray diffraction (XRD), Raman spectroscopy, scanning and transmission electronic microscopy (SEM; TEM), and X-ray photoemission Spectroscopy (XPS). XPS also allowed us to determine the Ni-based species formed as a function of the dopant loading. The HER activity of the materials was investigated by linear sweep voltammetry (LSV) in 0.5 M H2SO4 and 1.0 M KOH. By combining the physicochemical and electrochemical results, we concluded that the Ni sites have a different role in the HER mechanism and kinetics in acidic and in alkaline media. Thus, NiSx species are essential to promote HER in alkaline medium, whereas the Ni-Mo-S ones enhance the HER in acid medium.

Iron oxide@graphitic carbon core-shell nanoparticles embedded in ordered mesoporous N-doped carbon matrix as an efficient cathode catalyst for PEMFC

Developing electrocatalysts with high activity and long-term stability towards oxygen reduction reaction (ORR) in acidic media is still an important topic. However, most of the already reported non-precious-metal catalysts (NPMCs) for ORR exhibit excellent performance in basic media.In the present work, we report a newly designed FeOx@graphitic carbon core-shell structured nanoparticles implanted in N-doped carbon matrix, with ordered and mesoporous structure (FeOx@GC-NOMC), which i) exhibits a better electrocatalytic activity in acidic media, ii) follows a four-electron ORR process, and iii) shows superior stability and inertness to methanol when compared with commercial Pt/C (20 wt %). These features are mostly attributed to the following two points: i) the ordered mesoporous carbon matrix can not only be favorable for the rapid transfer and active sites exposure, but also limit the embedded nanoparticles size and avoid its agglomeration, and ii) the high content of “Fe-N” active sites, and the core-shell structure of embedded nanoparticles (FeOx@GC) can protect the active sites from the corrosion of harsh conditions and ensure the long-term durability.It is found that the as-prepared FeOx@GC-NOMC shows one of the best H2-O2 PEMFC single-cell performances, among all thetested and currently reported NPMCs, as well as a long-term durability. More precisely, at an open circuit potential of ca. 1 V, the peak power density reaches up to 350 W g−1 (1050 mW cm-2 based on active area). A slight current decay is observed after a chronoamperometric test of 120 h. The above features make FeOx@GC-NOMC a promising potential alternative to Pt/C for ORR electrocatalysis in practical fuel cell applications.

Oxygen reduction reaction mechanism and kinetics on M-NxCy and M@N-C active sites present in model M-N-C catalysts under alkaline and acidic conditions

M-N-C electrocatalysts (where M is Fe or Co) have been investigated for mitigating the dependence on noble metals when catalyzing the oxygen reduction reaction (ORR) for fuel cell technologies in acidic or alkaline conditions. Rotating disk and rotating ring-disk electrode measurements for Fe-N-C and Co-N-C catalysts demonstrate promising performances and stability for the ORR, while the activity of main suspected active sites (M-NxCy and M@N-C) has been discussed on the basis of the known physical-chemical properties of the catalysts in acid and alkaline media. Thereupon, it is observed that atomically dispersed Fe-NxCy sites reach the highest ORR activity in acid media when amplified by an adequate energy binding between the metallic center and the oxygenated reaction intermediates. In contrast, Fe@N-C core-shell sites reach a maximum ORR mass activity in alkaline media through a synergistic effect involving catalyst particles with metallic iron in the core and nitrogen-doped carbon in the shell.

Preparations of Highly Active Pd-Based Order Intermetallic Compounds and Relationship between Surface Structure and Electrocatalytic Activity

Pd-based structurally ordered phase nanoparticles (NPs)/carbon black (CB) were successfully prepared by reduction of precursors of Pd and secondary materials using ethylene glycol as a reducing agent and an annealing procedure. In one of our studies, we developed structurally ordered intermetallic PdCu3 which has Cu3Au type structure electrocatalysts with excellent ORR activity in acidic media. High electrocatalytic activity of ordered intermetallic PdCu3 was inspired by electrochemically dealloy process. This electrochemical phenomenon on high catalytic activity was discussed by both density functional theory calculations and X-ray photoelectron spectroscopy. In this poster session, we have summarized our recent results.

Non-PGM Electrocatalysts for Oxygen Reduction Reaction Inspired By Metalloenzyme Active Sites

Oxygen reduction reaction (ORR) is a key reaction in future energy generation devices such as polymer electrolyte fuel cells (PEFCs) and metal–air batteries. To drive the ORR in state-of-the-art PEFCs, platinum group metal (PGM) alloys have been used. Since platinum is rare and expensive, there is a need to develop highly active PGM-free ORR electrocatalysts for wide spread applications of PEFCs. In nature, catalytic active sites based on 3d transition metals are widely utilized as catalytic reaction centers in metalloenzymes: for example, laccases and cytochrome c oxidases are known to catalyze the ORR with almost no energy loss at the active sites of multinuclear metal complexes.[1,2] We present ORR electrocatalysts with multinuclear copper active sites incorporated in nitrogen-doped carbon nanosheets, which were inspired by the active site of laccases. Our copper-based electrocatalyst exhibited high ORR activity in alkaline aqueous solution. Physicochemical measurements including in situ X-ray absorption spectroscopy[3] revealed that multinuclear copper sites were embedded in nitrogen-doped carbon nanosheets and worked as the catalytic active center.[4] We also prepared a Fe–Cu-codoped carbon electrocatalyst inspired by the active site of cytochrome c oxidase.[5] Optimization of synthetic conditions and doping ratios of Fe to Cu into carbon resulted in the improvement of the ORR activity in acidic media. The electrocatalyst codoped with Fe and Cu showed higher ORR activity than those with Fe or Cu. Our bioinspired approaches will offer guidance for developing non-PGM ORR electrocatalysts with high activity.

Iron-Salt Thermally Emitted Strategy to Prepare Graphene-like Carbon Nanosheets with Trapped Fe Species for an Efficient Electrocatalytic Oxygen Reduction Reaction in the All-pH Range.

Earth-abundant, highly active, and durable electrocatalysts toward oxygen reduction reaction (ORR) in the all-pH range are highly required for practical application of electrochemical energy conversion technologies. Here, non-noble-metal graphene-like carbon nanosheets with trapped Fe species (Fe-N/GPC) are developed by an iron-salt thermally emitted strategy, which integrates the modulation of the electronic structure for boosted intrinsic activity with the engineering of hierarchical porosity for enriched active sites. The ORR electrocatalytic performance of Fe-N/GPC-800 achieves the half-wave potentials of 0.86 and 0.77 V with limiting current densities of 6.1 and 4.7 mA cm-2 in 0.1 M KOH and 0.1 M PBS solutions, respectively, as well as respectable stability. Furthermore, Fe-N/GPC-800 also shows considerable ORR catalytic activity in acid media accompanied by stability superior to those of Pt/C catalysts. The as-prepared Fe-N/GPC-800, as a cathodic catalyst, is assessed in a Zn-air battery test and delivers an open-circuit voltage of 1.44 V with a power density of 134 mW cm-2 as well as the outstanding durability after 350 cycles at 10 mA cm-2, demonstrating appreciable promise in application of metal-air batteries. This work provides an enabling and versatile strategy for facile and scale-up preparation of high-performance non-noble-metal electrocatalysts.

All-in-one surface engineering strategy on nickel phosphide arrays towards a robust electrocatalyst for hydrogen evolution reaction

Efficient hydrogen evolution reaction electrocatalysts based on inexpensive and earth-abundant elements could enable low-cost water splitting and H2 production, thus are compelling for the conversion of renewable electricity to fuels. In this work, we showcase the combinations of multiple surface engineering routes in a Ni2P electrocatalyst that achieves significantly enhanced catalytic performance. The surface roughness and structure disordering of the Ni2P arrays on carbon foil are precisely regulated by altering the annealing condition, resulting in a surface area-enlarged, defect-rich and superaerophobic catalytic surface. Density functional theory calculations are used to identify the effect of defective sites on the free energy for hydrogen adsorption in hydrogen evolution. Meanwhile, the superaerophobic surface is proved to accelerate removing gas bubbles on the electrode, thus facilitate the catalytic process. In addition, the enlarged surface area of material is considered to elevate the catalytic performance by providing more active sites in reaction. The designed catalyst obtained through a moderate treatment exhibits optimal electrocatalytic activity in acidic media: a low overpotential of 63 mV at 10 mA cm−2, small Tafel slope of 67 mV dec−1 and outstanding stability over 10 h. The synthetic strategy shows great promise to design efficient catalysts via subtle surface engineering.

Manganese and zinc ferrite based graphene nanocomposites for electrochemical hydrogen evolution reaction

MnFe2O4/Graphene and ZnFe2O4/Graphene Nanocomposites (MFG & ZFG) were synthesized by solvothermal route and further tested as promising electrocatalyst towards Hydrogen Evolution Reaction (HER). The morphology, structural and electrochemical activity of the nanocomposites were studied by X-ray Diffraction, Scanning electron microscopy, Transmission electron microscopy, Linear Sweep Voltammetry (LSV), Cyclic Voltammetry, Tafel polarization and Electrochemical Impedance Spectroscopy (EIS). MnFe2O4/Graphene and ZnFe2O4/Graphene nanocomposites were found efficient electrocatalysts for hydrogen generation via the hydrogen reduction mechanism. The nanocomposites exhibited good activity in acidic medium with a low over potential (313 mV and 315 mV) and a Tafel slope of 106.4 mVdecade−1 and 114.3 mVdecade−1 respectively. An exchange current density of 60.11 mAcm−2, 47 mAcm−2, TOF being 1.47H2/s and 1.09H2/s was observed for MFG and ZFG. Further, an electrochemical specific surface area of 1.51 mFcm−2, 0.3 mFcm−2 and a less charge transfer resistance value of 8.5Ω and 13.0Ω was calculated for MFG and ZFG electrocatalysts respectively. The kinetic parameters indicated that the reaction was governed by Volmer mechanism.

Theoretical and Experimental Investigations in Metal−N−C Composites for Oxygen Reduction Reaction and Hydrogen Evolution Reaction at Universal Phs

During the development of platinum group metal (PGM)-free electrocatalysts for both polymer electrolyte membrane fuel cells and electrolyzers, non-precious metal and nitrogen co-doped carbon (denoted as Me-N-C) has been widely investigated as a promising catalyst for oxygen reduction reactions (ORR)1-3 and hydrogen evolution reactions (HER)4. However, these studies were conducted by different groups under various experimental conditions and most of the experiments were focused on a certain kind of reaction (ORR or HER) in either acid or alkaline media. In addition, current understanding can not explain well the activity discrepancy between Fe-N-C and Co-N-C. For instance, the former is much active than the latter for ORR, while the trend is reversed for HER4. This study aims to solve this dilemma by a first-principles density functional theory (DFT) approach. In the theoretical simulations, the catalytic activities on Fe-N-C and Co-N-C were studied for ORR and HER in both acid and alkaline solutions by constructing the free energy diagrams. Meanwhile, the effect of applied potential on the activity was also included. Figure 1 shows the free energy diagrams of ORR for Fe-N-C and Co-N-C at low pH at 0 V (Fig. 1a) and 0.80 V (Fig. 1b), respectively. At 0 V, all elementary reaction steps are downhill for Fe-N-C (blue line) and Co-N-C (red line), indicating that both catalysts have good ORR activity in acid media; however, when the potential increases to 0.80 V, the OOH* and O* formation steps become uphill for Co-N-C while the Fe-N-C still possesses the downhill trend, illustrating the latter one has a better activity at low overpotentials. Similarly, the free energy diagrams based on the elementary reaction steps were constructed for ORR in alkaline media as well as the HER, from which the comparison between the Fe-N-C and Co-N-C regarding the ORR and HER activities at universal pHs could be obtained. Our DFT calculation results demonstrateed that Fe-N-C had the better ORR activity than Co-N-C in both acid and alkaline media but a completely different trend was found for HER. These theoretical findings were also verified by our experimental results. References (1) Wu, G.; More, K. L.; Johnston, C. M.; Zelenay, P. Science 2011, 332, 443. (2) Shao, M.; Chang, Q.; Dodelet, J.-P.; Chenitz, R. Chemical reviews 2016, 116, 3594. (3) Lefèvre, M.; Proietti, E.; Jaouen, F.; Dodelet, J.-P. science 2009, 324, 71. (4) Zhang, L.; Liu, W.; Dou, Y.; Du, Z.; Shao, M. The Journal of Physical Chemistry C 2016, 120, 29047. Figure 1. Gibbs free energy diagrams for ORR in acid media for Fe-N-C (blue) and Co-N-C (red) at 0 V (a) and 0.80 V (b). Figure 1

Metal-Nitrogen-Carbon Catalysts for Oxygen Reduction in PEM Fuel Cells: Self-Template Synthesis Approach to Enhancing Catalytic Activity and Stability

Proton exchange membrane fuel cells (PEMFCs) are leading candidates in the utilization of clean energy resources for application in transportation, stationary, and portable devices. In PEMFCs, cathode catalysts are crucial for overall performance and durability due to kinetically slow oxygen reduction reactions (ORR). Because platinum (Pt), a state-of-the-art ORR catalyst, is rare and expensive, the development of high-performance platinum metal group (PGM)-free catalysts is highly desirable for future fuel cell technologies. Among the various PGM-free catalyst formulations, metal and nitrogen co-doped carbon (M-N-C, M: Fe, Co, or Mn) catalysts have exhibited encouraging activity and stability in acidic media for ORR and possess great potential to replace Pt in the future. Therefore, based on our extensive experience in the field of ORR catalysis, this review will comprehensively summarize the basic principles in the design and synthesis of M-N-C catalysts for durable, inexpensive, and high-performance PEMFCs with an emphasis on Co- and Mn-N-C catalysts to avoid Fenton reactions between Fe2+ and H2O2, which can generate free radicals and lead to the degradation of catalysts, ionomers, and membranes in PEMFCs. Furthermore, template-free 3D hydrocarbon frameworks as attractive precursors to advanced M-N-C catalysts will be discussed to significantly enhance intrinsic ORR activities in acidic media. In addition, long-term performance durability of M-N-C cathodes will be discussed extensively to provide potential solutions to enhance catalyst stability in PEMFCs. Finally, this review will provide an overall perspective on the progress, challenges, and solutions of PGM-free catalysts for future PEMFC technologies.

PPT1 Promotes Tumor Growth and Is the Molecular Target of Chloroquine Derivatives in Cancer.

Clinical trials repurposing lysosomotropic chloroquine (CQ) derivatives as autophagy inhibitors in cancer demonstrate encouraging results, but the underlying mechanism of action remains unknown. Here, we report a novel dimeric CQ (DC661) capable of deacidifying the lysosome and inhibiting autophagy significantly better than hydroxychloroquine (HCQ). Using an in situ photoaffinity pulldown strategy, we identified palmitoyl-protein thioesterase 1 (PPT1) as a molecular target shared across monomeric and dimeric CQ derivatives. HCQ and Lys05 also bound to and inhibited PPT1 activity, but only DC661 maintained activity in acidic media. Knockout of PPT1 in cancer cells using CRISPR/Cas9 editing abrogates autophagy modulation and cytotoxicity of CQ derivatives, and results in significant impairment of tumor growth similar to that observed with DC661. Elevated expression of PPT1 in tumors correlates with poor survival in patients in a variety of cancers. Thus, PPT1 represents a new target in cancer that can be inhibited with CQ derivatives. SIGNIFICANCE: This study identifies PPT1 as the previously unknown lysosomal molecular target of monomeric and dimeric CQ derivatives. Genetic suppression of PPT1 impairs tumor growth, and PPT1 levels are elevated in cancer and associated with poor survival. These findings provide a strong rationale for targeting PPT1 in cancer. This article is highlighted in the In This Issue feature, p. 151.

Activating MoS2 Basal Plane with Ni2P Nanoparticles for Pt‐Like Hydrogen Evolution Reaction in Acidic Media

Abstract2D molybdenum disulfide (MoS2) displays a modest hydrogen evolution reaction (HER) activity in acidic media because the active sites are limited to a small number of edge sites with broader basal planes remaining mostly inert. Here, it is reported that the MoS2 basal planes could be activated by growing nickel phosphide (Ni2P) nanoparticles on them. Thus a Ni2P/MoS2 heterostructure is constructed via in situ phosphidation of an indigenously synthesized NiMoS4 salt as a single precursor to form a widely cross‐doped and chemically connected heterostructure. The conductivity and stability of the Ni2P/MoS2 heterostructure are further enhanced by hybridization with conductive N‐doped carbon supports. As a result, the Ni2P/MoS2/N:RGO or Ni2P/MoS2/N:CNT electrocatalyst displays Pt‐like HER performance in acidic media, outperforming the incumbent best HER electrocatalyst, Pt/C, in a more meaningful high current density region (>200 mA cm−2) making them a promising candidate for practical water electrolysis applications. Since nonprecious metal catalysts showing Pt‐like HER performance in acidic media are rare, the Ni2P/MoS2 heterostructure catalyst is a promising candidate for practical hydrogen production via water electrolysis.

Moderate Adsorption of Oxygen Molecular Induced Better Performance of Oxygen Reduction Reaction

As an oxygen reduction reaction (ORR) catalyst, the activity in acid medium of nitrogen and sulphur co-doped graphene with carbon defect (V-N,S-gra) is investigated via density functional theory (DFT), including the activity sites, the reaction pathways as well as free energy diagrams. Based on the spin-polarized calculations, six kinds of O2 adsorption configurations are found and the reaction sites are all carbon atoms adjacent to the dopants. However, they are physisorption in the neighboring carbon of nitrogen, unlikely to initialize the ORR process. Otherwise, if the adsorption sites are in the adjacent carbon of sulphur, the catalyst activity is associated with the adsorption energy, that is, we find a best ORR pathway with a gentle adsorption (−0.03eV). An energy barrier of 0.82eV is found in this favorable process in which the adsorbed O2 molecular is prone to be hydrogenated continuously to give rise to H2O molecular, promising a four-electron pathway. On the other hand, in the O2 strongly adsorbed configurations, the intermediate *OH is not easily to be hydrogenated in the final step. At last, the effect of electrode potential is simulated and for the best reaction pathway all the elemental reactions are downhill until the potential is as large as 0.31eV.

Effect of Pyrolysis Atmosphere and Electrolyte pH on the Oxygen Reduction Activity, Stability and Spectroscopic Signature of FeNx Moieties in Fe-N-C Catalysts

Two Fe-N-C catalysts comprising only atomically-dispersed FeNx moieties were prepared, differing only in the fact that the second catalyst (Fe0.5-NH3) was obtained by subjecting the first one (Fe0.5-Ar) to a short pyrolysis in ammonia. While the initial ORR activity in acid medium in rotating disk electrode is similar for both catalysts, the activity in alkaline medium is significantly higher for Fe0.5-NH3. Time-resolved Fe dissolution reveals a circa 10 times enhanced Fe leaching rate in acidic electrolyte for Fe0.5-NH3 relative to Fe0.5-Ar. Furthermore, for the former, the leaching rate is strongly enhanced when the electrochemical potential is in the range 0.75–0.3 V vs. RHE. This may explain the reduced stability of ammonia-pyrolyzed Fe-N-C catalysts in operating PEMFCs. In alkaline medium in contrast, Fe0.5-NH3 is more active and more stable, with minimized Fe leaching during electrochemical operation in load-cycling mode. Operando X-ray absorption spectroscopy measurements in alkaline electrolyte reveals similar trends of the XANES and EXAFS spectra as a function of the electrochemical potential for both catalysts, but the magnitude of change is much less for Fe0.5-NH3, as evidenced by a Δμ analysis. This is interpreted as a lower average oxidation state of FeNx moieties in Fe0.5-NH3 at open circuit potential.

Pyrolysis of Self-Assembled Iron(III) Porphyrin on Carbon toward Efficient Oxygen Reduction Reaction

We report a simple solubility-induced self-assembly of iron(III) meso-5,10,15,20-tetrakis(4-carboxyphenyl)porphyrin (FeCPP) on carbon black (BP2000) combined with subsequent pyrolysis, leading to the synthesis of new types of non-precious metal electrocatalysts (NPMEs). In both alkaline and acidic media, the obtained NPMEs demonstrate oxygen reduction reaction (ORR) activity comparable to that of commercial 20% Pt/C and much better than that synthesized by pyrolysis of mechanically blended FeCPP and carbon without self-assembly. Especially, the half-wave potential of our electrocatalyst is 0.79 V (vs. RHE) in 0.1 M HClO4 aq., representing a highly active NPME in acid. Additionally, our electrocatalysts are superior to commercial Pt/C in terms of durability during accelerated durability test (ADT) in both acidic and alkaline media. The H2O2 and HO2− yield of the electrocatalyst is less than 6.5% and 0.8%, respectively, in acidic and alkaline media. The high ORR activity should be closely correlated with the self-assembly process, allowing well dispersion of FeCPP on carbon and forming a relatively high density of ORR active sites after pyrolysis. Interestingly, it appears that Fe-N-C sites and iron oxides should be the major contributor of the ORR activity in acidic media based on electrochemical SCN− poisoning and acid-treatment experiments.