Catalytic conversion of cellulose into ethylene glycol over supported carbide catalysts

In the current paper we present a combined catalytic and surface science studies to evaluate the utilization of carbide catalysts for the conversion of cellulose to polyols, especially to ethylene glycol (EG). Based on catalytic studies over a W₂C catalyst, the EG yield has been optimized by varying H₂ pressure, reaction temperature and time. The catalytic performance has been compared for several types of supported catalysts, including tungsten carbides, molybdenum carbides and platinum on different supports. Among all the catalysts, tungsten carbide supported on activated carbon, W₂C/AC, shows the highest EG yield, which is further enhanced to 61% with the promotion of Ni. The corresponding surface science studies indicate that the enhanced EG yield is at least partially due to a weaker bonding between EG and Ni-promoted tungsten carbide surface.     

Highly Durable Platinum based Cathode Electrocatalysts for PEMFC Application using Oxygen and Nitrogen Functional Groups Attached Nanocarbon Supports

The combined effect of oxygen and nitrogen functional groups on highly crystalline carbon supports like multiwalled carbon nanotubes (MWCNT) and MWCNT‐few layer graphene hybrid structures (MWCNT+FLG) have been investigated towards oxygen reduction reaction (ORR) performance and carbon corrosion durability in polymer electrolyte membrane fuel cell (PEMFC) applications. The pristine carbon supports were modified with oxygen and nitrogen functionalities by treating with concentrated mineral acids and subsequent nitrogen plasma treatment assisted with R.F. magnetron sputtering. Pt nanoparticles were dispersed over these chemically modified carbon supports by polyol reduction method. The physicochemical properties of as synthesized electrocatalysts were studied by different techniques such as XRD, TEM, FTIR, Raman and XPS. Electrochemical properties were investigated by cyclic voltammetry and linear sweep voltammetry in 0.1M HClO₄ medium. Compared to commercial Pt/C catalysts, durability show ∼30 % enhancement for the as prepared electrocatalysts due to the presence of large amount of pyrrolic nitrogen and highly oriented graphitic nature of the catalyst supports. The ORR performance were comparable with Pt/C (TEC10E30E) in terms of MSA, 259, 270, 252 A g⁻¹ for Pt/C, Pt/N‐f‐MWCNT, Pt/N‐f‐(MWCNT+FLG) respectively.     

Methanol-tolerant PdPt/C alloy catalyst for oxygen electro-reduction reaction

A carbon-supported Pd-based PdPt catalyst (PdPt/C) with a small amount of Pt was prepared by borohydride reduction method and its activity in the oxygen electro-reduction reaction (ORR) was investigated in acidic conditions both with and without methanol. For comparison, carbon-supported Pt (Pt/C) and Pd (Pd/C) catalysts were prepared and the ORR activities were compared. Results revealed that the PdPt/C catalyst showed slightly lower ORR activity in terms of onset potential of oxygen reduction than Pt/C catalyst in 0.1M HClO₄. However, PdPt/C catalyst exhibited enhanced activity toward selective ORR with methanol-tolerant characteristics in 0.1M HClO₄ in the presence of methanol. The PdPt/C catalyst prepared here is suitable for use as a cathodic electrocatalyst in direct alcohol fuel cells after addition of small amount of expensive Pt metal.     

Activity,selectivity, and methanol tolerance of novel carbon-supported Pt and Pt<Subscript>3</Subscript>Me (Me = Ni,Co) cathode catalysts

The activity, selectivity, and methanol tolerance of novel, carbon supported high-metal loading (40 wt.%) Pt/C and Pt₃Me/C (Me = Ni, Co) catalysts for the O₂ reduction reaction (ORR) were evaluated in model studies under defined mass transport and diffusion conditions, by rotating (ring) disk and by differential electrochemical mass spectrometry. The catalysts were synthesized by the organometallic route, via deposition of pre-formed Pt and Pt₃Me pre-cursors followed by their decomposition into metal nanoparticles. Characteristic properties such as particle sizes, particle composition and phase formation, and active surface area, were determined by transmission electron microscopy, energy dispersive X-ray spectroscopy, X-ray photoelectron spectroscopy, and X-ray diffraction. For comparison, commercial Pt/C catalysts (20 and 40 wt.%, E-Tek, Somerset, NJ, USA) were investigated as well, allowing to evaluate Pt loading effects and, by comparison with the pre-cursor-based catalyst with their much smaller particle sizes (1.7 nm diameter), also particle size effects. Kinetic parameters for the ORR were evaluated; the ORR activities of the bimetallic catalysts and of the synthesized Pt/C catalyst were comparable and similar to that of the high-loading commercial Pt/C catalyst; at typical cathode operation potentials H₂O₂ formation is negligible for the synthesized catalysts. Due to their lower methanol oxidation activity the bimetallic catalysts show an improved methanol tolerance compared to the commercial Pt/C catalysts. The results indicate that the use of very small particle sizes is a possible way to achieve reasonably good ORR activities at an improved methanol tolerance at DMFC cathode relevant conditions.     

Nano-stuctured Pt-Fe/C as cathode catalyst in direct methanol fuel cell

Pt-Fe/C catalysts were prepared by a modified polyol synthesis method in an ethylene glycol (EG) solution, and then were heat-treated under H₂/Ar (10 vol.%) at moderate temperature (300 °C, Pt-Fe/C300) or high temperature (900 °C, Pt-Fe/C900). As comparison, Pt-Fe/C alloy catalyst was prepared by a two-step method (Pt-Fe/C900B). X-ray diffraction (XRD) and transmission electron microscopy (TEM) images show that particles size of the catalyst increases with the increase of treatment temperatures. Pt-Fe/C300 catalyst has a mean particle size of 2.8 nm (XRD), 3.6 nm (TEM) and some Pt-Fe alloy was partly formed in this sample. Pt-Fe/C900B catalyst has the biggest particle size of 6.2 nm (XRD) and the best Pt-Fe alloy form. Cyclicvoltammetry (CV) shows that Pt-Fe/C300 has larger electrochemical surface area than other Pt-Fe/C and the highest utilization ratio of 76% among these Pt-based catalysts. Rotating disk electrode (RDE) cathodic curves show that Pt-Fe/C300 has the highest oxygen reduction reaction (ORR) mass activity (MA) and specific activity (SA), as compared with Pt/C catalyst in 1.0 M HClO₄. However, Pt-Fe/C catalyst does not appears to be a more active catalyst than Pt/C for ORR in 1.0 M HClO₄ + 0.1 M CH₃OH. Pt-Fe/C300 exhibits higher ORR activity and better performance than other Pt-Fe/C or Pt/C catalysts when employed for cathode in direct methanol single cell test, the enhancement of the cell performance is logically attributed to its higher ORR activity, which is probably attributed to more Pt⁰ species existing and Fe ion corrosion from the catalyst.     

Electroreduction of dioxygen (ORR) in alkaline medium on Ag/C and Pt/C nanostructured catalysts—effect of the presence of methanol

Ag/C catalysts with different loading were prepared using a colloidal route to obtain well dispersed catalysts on carbon, with a particle size close to 15 nm. An amount of 20 wt.% Ag on carbon was found to be the best loading in terms of current density and mass activity. The 20 wt.% Ag/C catalyst was then studied and the kinetics towards ORR was determined and compared with that of a 20 wt.% Pt/C catalyst. The number of exchanged electrons for the ORR was found to be close to four with the rotating disk electrode (RDE) as well as with the rotating ring disc electrode (RRDE) techniques. From the RDE results, the Tafel slopes b, the diffusion limiting current density inside the catalytic film (j_l^film) and the exchange current density (j₀) were evaluated. The Tafel slopes b and diffusion limiting current densities inside the catalytic film (j_l^film) were found to be in the same order for both catalysts, whereas the exchange current density (j₀), which is a suitable estimation of the activity of the catalyst, was at least 10 times higher at the Pt/C catalyst than at the Ag/C catalyst. The behavior of both catalysts in methanol containing electrolyte was investigated and it was found that at a low methanol concentration, the Pt/C catalyst was quasi-tolerant to methanol. But, at a high methanol concentration, the ORR at a Pt/C was affected. However, the Pt/C catalyst showed in each case better activity towards ORR than the Ag/C catalyst, even if the latter one was less affected by the presence of methanol than the former one.     

Study of Methanol‐tolerant Oxygen Reduction Reaction at Pt–Bi/C Bimetallic Nanostructured Catalysts

The nanostructured platinum–bismuth catalysts supported on carbon (Pt₃Bi/C, PtBi/C and PtBi₃/C) were synthesised by reducing the aqueous metal ions using sodium borohydride (NaBH₄) in presence of a microemulsion. The amount of metal loading on carbon support was found to be 10 wt.‐%. The catalyst materials were characterised by X‐ray diffraction (XRD), X‐ray fluorescence (XRF), transmission electron microscope (TEM) and electroanalytical techniques. The Pt₃Bi/C, PtBi/C and PtBi₃/C catalysts showed higher methanol tolerance, catalytic activity for oxygen reduction reaction (ORR) than Pt/C of same metal loading. The electrochemical stability of these nano‐sized catalyst materials for methanol tolerance was investigated by repetitive cycling in the potential range of –250 to 150 mV_MSE. Bi presents an interesting system to have a control over the activity of the surface for MOR and ORR. All Pt–Bi/C catalysts exhibited higher mass activities for oxygen reduction (1–1.5 times) than Pt/C. It was found that PtBi/C catalyst exhibits better methanol‐tolerance than the other catalysts.     

Electrocatalysis of oxygen reduction on a carbon supported platinum-vanadium alloy in polymer electrolyte fuel cells

The electrocatalysis of the oxygen reduction reaction (ORR) on carbon supported Pt:V 1:1 catalyst in polymer electrolyte fuel cells (PEFC) was investigated. At an oxygen pressure of 1 atm results indicate a lower electrocatalytic activity for the ORR in the presence of vanadium. However, at an O₂ pressure ≥2 atm an enhanced electrocatalytic property of PtV/C compared with Pt/C is revealed. This result indicates the occurrence of a different electrocatalytic mechanism for the ORR on Pt/C and PtV/C. An increase of mass transport overpotentials is observed for the PtV/C catalyst, and this was related to the presence of vanadium oxide. Indeed, XRD analysis revealed that only about 30% of V present in the catalyst is alloyed with Pt, forming a face centred cubic (fcc) Pt₃V solid solution. A thermal treatment at 850 °C under reducing atmosphere leads to the formation of an ordered fcc Pt₂V phase. After this, the ORR activity of PtV/C at O₂ pressure 1 atm is higher than that of Pt/C.     

On the influence of Pt particle size on the PEMFC cathode performance

Colloidal suspensions of almost spherical and crystalline Pt nanoparticles between 1.6 and 2.6 nm in diameter and with narrow size distribution were synthesized using the phase transfer method (PTM) with alkylamines, C_nNH₂, as stabilizing agents. Batches of such homogenous Pt-C_nNH₂ (n = 8, 12) nanocrystals were deposited onto Vulcan XC-72 carbon powder, and the activity for the oxygen reduction reaction (ORR) of this series of Pt/C materials was evaluated under PEMFC conditions. The aim was to elucidate whether this type of stabilized Pt nanoparticles were as active for the ORR as a corresponding commercial Pt/C material, and if any difference in mass activity could be observed between catalysts with different Pt particle size. In the PEMFC experiments, i.e. voltammetry in oxygen and nitrogen, it was found that, after an initial electrode activation, the ORR activity of the catalysts prepared from the alkylamine-stabilized Pt nanoparticles deposited on carbon was as high as that of the employed commercial reference catalyst. In fact, all samples in the Pt/C series showed high and very similar ORR activity normalized to Pt-loading, without significant dependence on the initial Pt particle size. However, pre- and post-electrochemical characterization of the Pt/C material series with TEM showed that structural changes of the Pt nanoparticles occurred during electrochemical evaluation. In all samples studied the mean Pt particle size increased during the electrochemical evaluation resulting in decreased differences between the samples explaining the observed similar ORR performance of the different materials. These results emphasize the necessity of post-operation characterization of fuel cell catalysts when discussing electrocatalytic activity. In addition, employing complex preparation efforts for lowering the Pt particle size below 3 nm may have limited practical value unless the particles are stabilized from electrochemical sintering.     

Effect of pre-treatment approach of a carbon support on activity of PtSn/C electrocatalysts for direct ethanol fuel cells

Vulcan XC-72R carbon was pretreated using acid and thermal activation methods, and the carbons obtained were used as supports for a PtSn/C catalyst synthesized by a successive reduction process. Surface characteristics of the supports, including BET surface area, pH_PZC and functional group, were analyzed using physical N₂ adsorption, mass titration, acid–base titration, and Fourier transform infrared (FTIR) spectrometer technique, respectively. The prepared PtSn/C catalysts were characterized by X-ray diffractometer (XRD), energy dispersive X-ray spectrometer (EDX), inductively coupled plasma–atomic emission spectrometry (ICP–AES), and transmission electron microscope (TEM) techniques, and then were examined for their behavior under ethanol oxidation as well as for their performance in a direct ethanol fuel cell (DEFC). The results showed that pretreatment by HNO₃ produced various oxygenated functional groups on the support surface and increased its acidic property. The strong acidity of the acid-treated support led to an unfavorable condition for the Pt reduction reaction and resulted in low Pt content but high Pt:Sn ratio in the PtSn/C catalyst. On the other hand, thermal activation increased the base functional groups on the carbon surface, which enhanced reduction of Pt precursor, and consequently, provided a small average metal particle size of 2.2 nm. The results from cyclic voltammetry, chronoamperometry and cell performance testing confirmed that the catalytic activity for ethanol oxidation and the performance in the direct ethanol fuel cell of the heat-treated carbon-supported PtSn catalyst was superior to the fresh PtSn/C catalyst and the acid-treated carbon-supported PtSn catalyst.     

Properties of Pt/C catalyst modified by chemical vapor deposition of Cr as a cathode of phosphoric acid fuel cell

Cr-modified Pt/C catalysts were prepared by the chemical vapour deposition (CVD) of Cr on Pt/C, and their performance as a cathode of phosphoric acid fuel cell (PAFC) was compared with the case of catalysts containing Cr added by impregnation (IMP).The catalyst prepared by CVD showed a higher activity for oxygen reduction reaction (ORR) than one prepared by IMP. There was an optimum amount of Cr that yielded the maximum mass activity of the catalyst because the gain in the intrinsic activity due to the promotional effect of Cr was counterbalanced by the loss of exposed Pt surface area as a result of the Cr introduction. Nevertheless, the activity increase at the optimum amount of Cr was greater for the CVD catalyst than for the IMP catalyst. Also, the optimum amount of Cr to yield the maximum activity was smaller for the former catalyst [Cr/Pt]_CVD = 0.6, than for the latter, [Cr/Pt]_IMP = 1.0.The enhancement of the Pt catalyst activity by Cr addition is attributed to two factors: changes in the surface Pt-Pt spacing and the electronic modification of the Pt surface. The formation of a Pt-Cr alloy, as confirmed by X-ray diffraction, decreased the lattice parameter of Pt, which was beneficial to the catalyst activity for ORR. X-ray photoelectron spectroscopy results showed that the binding energies of Pt electrons were shifted to higher energies due to Cr modification. Accordingly, the electron density of Pt was lowered and the Pt-O bond became weak on the Cr-modified catalysts, which was also beneficial to the catalyst activity for ORR.The promotion of oxygen reduction on Cr-modified catalysts was confirmed by measuring the cyclic voltammograms of the catalysts. All the above changes were made more effectively for catalysts prepared by CVD than for those prepared by IMP because the former method allowed Cr to interact more closely with the Pt surface than the latter, which was demonstrated by the characterization of catalysts in this study.     

Pt/WC-CNTs催化剂的制备及其对氧还原的电催化性能

通过表面修饰和还原碳化技术制备了以WC为主相的碳化钨/碳纳米管材料（WC-CNTs）,并进一步采用微波多元醇法载铂制备复合催化剂Pt/WC-CNTs。该催化剂相比于Pt/CNTs催化剂,具有更低的过电位、更大的电流密度和交换电流密度,且具有更小的电荷转移电阻和更好的氧还原选择性,显示了优异的氧还原电催化性能。XRD结果表明催化剂由多晶面的WC、Pt晶粒和CNTs组成,TEM和HRTEM显示细小的Pt颗粒均匀地分布在WC-CNTs表面。Pt颗粒和WC颗粒紧密接触,这有利于它们之间的催化协同效应,从而大大增强了Pt的氧还原催化活性。旋转圆盘电极研究结果表明Pt/WC-CNTs催化剂对氧还原反应为直接四电子过程。碳化钨/碳纳米管载铂催化剂性能优异、成本较低,在燃料电池阴极催化剂的研究应用中具有良好的发展前景。     

Characterization of methanol-tolerant Pd–WO3 and Pd–SnO2 electrocatalysts for the oxygen reduction reaction in direct methanol fuel cells

Palladium (Pd) catalysts containing nanosized metal oxides, tungsten oxide (WO₃) and tin oxide (SnO₂), supported on carbon black (Pd–MO_x/C) were synthesized, and the effect of the metal oxide on the oxygen reduction reaction (ORR) in a direct methanol fuel cell (DMFC) was investigated. The SEM images showed that the Pd nanoparticles were highly dispersed on the carbon black, and the metal oxide particles were also distributed well. Pd/C and Pd–WO₃/C catalysts as cathode materials for the ORR in DMFCs showed activity similar to or better than that of Pt/C, whereas Pd–SnO₂/C showed no improvement in catalytic activity.     

The construction of nitrogen-doped graphitized carbon–TiO2 composite to improve the electrocatalyst for methanol oxidation

The exploration of advanced catalyst supports is a promising route to obtain electrocatalysts with high activity and durability. Herein, the nitrogen-doped graphitized carbon/TiO₂ composite was fabricated and explored as support for the Pt catalyst. The composite support was constructed by carbonization of polypyrrole/TiO₂ using cobalt nitrate and nickel nitrate as graphitizing catalysts. The resulting catalyst shows enhanced electrocatalytic performance for methanol electrooxidation compared with the commercial Pt/C catalyst. The enhancement can be ascribed to combinatory effect of N-doped graphitized carbon and TiO₂, in which the tolerance to CO-poisoning and the intrinsic kinetics of methanol oxidation reaction were simultaneously improved by the bifunctional effect and the modification of the electronic structure. As a result, the as-developed nitrogen-doped graphitized carbon/TiO₂ composite present attractive advantages for the application in fuel cell electrocatalyst.     

Durable Transition‐Metal‐Carbide‐Supported Pt–Ru Anodes for Direct Methanol Fuel Cells

Molybdenum carbide (MoC) and tungsten carbide (WC) are synthesized by direct carbonization method. Pt–Ru catalysts supported on MoC, WC, and Vulcan XC‐72R are prepared, and characterized by X‐ray diffraction, X‐ray photoelectron spectroscopy, and transmission electron microscopy in conjunction with electrochemistry. Electrochemical activities for the catalysts towards methanol electro‐oxidation are studied by cyclic voltammetry. All the electro‐catalysts are subjected to accelerated durability test (ADT). The electrochemical activity of carbide‐supported electro‐catalysts towards methanol electro‐oxidation is found to be higher than carbon‐supported catalysts before and after ADT. The study suggests that Pt–Ru/MoC and Pt–Ru/WC catalysts are more durable than Pt–Ru/C. Direct methanol fuel cells (DMFCs) with Pt–Ru/MoC and Pt–Ru/WC anodes also exhibit higher performance than the DMFC with Pt–Ru/C anode.     

Tungsten and nickel tungsten carbides as anode electrocatalysts

Tungsten and nickel tungsten carbides were evaluated as the anode catalysts of a polymer electrolyte fuel cell (PEFC). These catalysts were prepared by the temperature-programmed carburization of tungsten and nickel tungsten oxides from 573 to 873-1073 K in a stream of 20% CH₄/H₂ and kept at temperature for 3 h. The 30% tungsten and nickel tungsten carbides mixed with Ketjen carbon (KC) were evaluated by cyclic voltammetry and linear sweep voltammetry using a rotating disk electrode and electrocatalytic activity (I-V performance) using a single cell. The W1023/KC catalyst achieved a power density of 6.4 mW/cm² (current density: 15.2 mA/cm²) which corresponded to 5.7% of that achieved by a commercial 20% Pt/C catalyst in a single cell (20% Pt/C: 111.7 mW/cm²) using our setup. From the XRD data, α-W₂C together with a small amount of WC was active during the anodic oxidation. The maximum power density of the 30 wt% 873 K-carburized NiW/KC was 8.2 mW/cm² at the current density of 19.0 mA/cm² which was 7.3% of the 20 wt% Pt/C.     

Ordered mesoporous carbons with controlled particle sizes as catalyst supports for direct methanol fuel cell cathodes

The ordered mesoporous carbons (OMCs) with various primary particle sizes were synthesized and the effect of the particle size of the OMC supports on their performance for the oxygen reduction reaction (ORR) in direct methanol fuel cells was investigated. The ordered mesoporous silica (OMS) templates with particle sizes of 100, 300, and 700 nm (OMS-100, -300, and -700) were synthesized by changing the synthesis pH and Na content in the silica source, sodium silicate. The OMCs with similar particle sizes and morphologies (OMC-100, -300, and -700) were faithfully replicated by using the corresponding OMSs as templates and phenanthrene as a carbon source. Structural characterizations revealed that three OMCs exhibit uniform mesopores of 4–5 nm and BET surface areas of 600–800 m² g⁻¹. The Pt nanoparticles of ca. 3 nm were supported onto these OMCs and the resulting Pt/OMC catalysts were tested for the ORR. The three OMC supported catalysts exhibited the catalyst utilization efficiencies and ORR activities of similar range, with the values of Pt/OMC-300 catalyst being slightly higher than the other two catalysts.     

Mesoporous carbons as low temperature fuel cell platinum catalyst supports

Platinum catalysts supported on ordered mesoporous carbons (OMC) are described. The mesoporous carbon support, CMK3 type, was synthesised as an inverse replica of a SBA-15 silica template. The platinum catalysts (i.e. Pt 20 wt% and Pt 10 wt%, respectively), obtained through a conventional wet impregnation method, have been investigated to determine their structural characteristics and electrochemical behaviour. The electro-catalytic performance towards the oxygen reduction reaction (ORR) was compared to those of commercial Pt/C-Vulcan XTC72R (E-Tek) catalysts with the same Pt wt%, under the same experimental conditions. The two catalyst samples have allowed the effect of the variation of both the Pt to Nafion and Pt to the supporting carbon ratios to be studied. Electrochemical tests have been carried out in three different systems: a catalyst ink deposited on a glassy carbon rotating disk electrode (RDE), a gas diffusion electrode (GDE) in a three-electrode cell with H₂SO₄ as the electrolyte and a complete PEM single fuel cell. The first results indicate that the OMC performs slightly less well than commercial carbon supports, mainly in the complete fuel cell system. The data from the cell tests indicate a less effective distribution of Nafion on the OMC surface which, probably, decreases the platinum utilisation and the proton conductivity.     

Combinatorial Search for Quaternary Methanol Tolerant Oxygen Electro‐Reduction Catalyst

A combinatorial library containing 645 different compositions was synthesised and characterised for methanol tolerant oxygen electro‐reduction reaction (ORR) catalytic performance. The library was composed of compositions involving between 1 and 4 metals among Pt, Ru, Fe, Mo and Se. In an optical screening test, Pt(50)Ru(10)Fe(20)Se(10) composition exhibited the highest ORR activity in the presence of methanol. This composition was further investigated by synthesis and characterisation of a powder version catalyst [Pt(50)Ru(10)Fe(20)Se(10)/C]. At 0.85 V [vs. reversible hydrogen electrode (RHE)] in the absence of methanol, the Pt/C catalyst exhibited higher ORR current (0.0990 mA) than the Pt(50)Ru(10)Fe(20)Se(10)/C catalyst (0.0902 mA). But much higher specific activity (12.7 μA cm_pt^–2) was observed in the Pt(50)Ru(10)Fe(20)Se(10)/C catalyst than for the Pt/C catalyst 6.51 μA cm_pt^–2). In the presence of methanol, the ORR current decreased by 0.0343 and 0.247 mA for the Pt(50)Ru(10)Fe(20)Se(10)/C and Pt/C catalysts, respectively, which proved the excellent methanol tolerance of the Pt(50)Ru(10)Fe(20)Se(10)/C catalyst.     

Exploration of the catalytically active site structures of animal biomass-modified on cheap carbon nanospheres for oxygen reduction reaction with high activity,stability and methanol-tolerant performance in alkaline medium

Nitrogen-doped carbon materials are known to exhibit good electrocatalytic activity for the oxygen reduction reaction (ORR). However, the structure of the active site for the ORR remains unknown. In this work, a series of nitrogen-doped carbon nanospheres (N-CNSs) were successfully prepared by using porcine blood protein as specific nitrogen source at different pyrolysis temperatures. The results show that the catalyst with a higher percentage of the planar N species (83.5% in total nitrogen content), possesses outstanding ORR electrocatalytic activity close to the commercial 40% Pt/C catalyst in alkaline media, and significantly superior stability and immunity for methanol crossover than that of 40% Pt/C. Metal Fe particles in the precursor can facilitate the partial transformation of oxidized N to planar N and the joint incorporation of planar pyridinic and pyrrolic N groups into the carbon matrix during high-temperature pyrolysis, which further produces more defective and exposed edges in the carbon structure. It is here proposed that both planar pyridinic and pyrrolic nitrogen atoms may be the N functionalities that are most responsible for the ORR electrocatalytic activity and can function as ORR active sites for as-prepared catalysts.