(Invited) Kinetic Parameters in Anion-Exchange Membrane Fuel Cells

Amazing progress has been achieved in the past two years of intensive research on Anion-Exchange Membrane (AEM) Fuel Cells (AEMFCs), bringing this technology significantly closer to the required levels for practical use in automotive (and other) applications. In material-related space, recent studies reported novel techniques for characterizing AEMs for fuel cells [1], as well as robust AEMs with hydroxide conductivities of 300 mS/cm [2]. In addition, new ionomeric materials and functional groups with increasing stability were introduced [3-5], and better Pt-free and PGM-free promising catalysts were developed [6-10]. On the fuel cells front, new AEMFCs based on CRM-free catalysts were successfully demonstrated [11-12], cells with record high power density outputs were obtained [13], materials able to operate under high-temperature AEMFC (HT-AEMFC) operation mode were reported [14], simulated materials and conditions to achieve AEMFC lifetime of 5,000-15,000 hours were theoretical demonstrated [15-16], and cell life time of 2,000 hours of continuous operation was already experimentally proven [17]. Altogether, the research community has made very impressive progress in such a short period of time. Having said that, we are not yet there; several remaining challenges should still be overcome in order to allow this technology to be a serious alternative to the mainstream PEMFC technology. To achieve that goal, we need (A) catalysts with higher activity towards hydrogen oxidation and oxygen reduction reactions to accomplish a full PGM-free (and even CRM-free) AEMFC; (B) a better understanding of carbonation issues while operating AEMFC with ambient air; and, (C) ionomeric materials with higher alkaline stability at higher temperatures. We, at Technion, focus our efforts on these (and other related) research topics, aiming to make a significant impact on the fuel cell research community. The latest achievements of our group in these AEMFC challenging fronts will be presented and discussed during the talk.

I was fortunate to have many technical discussions with Russ Kunz over the years and learnt a lot from him. Russ was a rarely encountered combination of scientist and technologist , a combination which is prerequisite for being a leader, as he was, in the field of fuel cell development. I chose the subject of this talk having been a common theme in our technical discussions, as Russ was the house expert at UTC for the alkaline fuel cells (AFCs) used in space applications, whereas I got intrigued in recent years by the potential of alkaline membrane fuel cells ( AMFCs) which share key features with the AFC while aiming to operate with no liquid electrolyte. The talk will accordingly review first some interesrting key features of materials and processes in AFCs about which I learnt to large degree from discussions with Russ. The first subject is the ORR in highly alkaline electrolytes and why gold is actually the active catalyst component in AFCs , being used as a AuPt alloy with the Pt serving basically just to harden the metal catalyst particles. The high activity of gold as ORR catalyst in alkaline media, does not fit the extensively taught volcano shaped relationship between M-O bond strength and ORR rate at a metal M. Gold is way down on the descending branch of the volcano plot in acid electrolyte, but is more active than Pt in alkaline media. This has been explained by the stabilization of a peroxide anion intermediate formed in alkaline electrolytes (HO2- or O2=) on the electrolyte side of the metal electrolyte interface, thereby removing the need of significant M-O interaction to stabilize the HOOads intermediate formed in acid. This opens the door for metals of very low affinity to oxygen to become very active ORR electrocatalysts thanks to the low overpotential they require to generate oxide free metal sites. In the case of the AMFCs, this high activty of coinage metals in alkaline environment is the basis for the possible choice of silver as ORR electrocatalyst, having activity in alkaline electrolyte comparable to Pt, at a market price which is about 1% that of Pt. One central aspect which is quite different in AFCs and AMFCs, is water managment. The AMFC presents a significant challenge of combined tendencies for cathode dry-out and anode flooding, originating form the cell water product forming in the anode ( fuel side) and consumed by the electrode process in the cathode ( air side). The resulting demands of water diffusivity through the cell membrane as well as electrode structures required to achieve passive control of the water profile in the AMFCs , staisfying the ORR consumption and ionomer hydration demands, will be described. Finally, the HOR in alkaline media in general and in the AMFC in particular has received significant attention recently. The rate of the HOR at Pt in 0.1-1MKOH solutions is significantly lower vs. the rate in acid. However, AMFC polarization curves to be presented show a performance that is not much below that of PEMFC in operation on hydrogen and air. This is achieved with HOR catalyzed by very low loadings of Pt in the form of alloy ( or other combination ) with an oxophilic metal component which facilitates completion of the HOR process and, securing optimized cell hydration under current.

Anion exchange membrane fuel cells (AEMFCs) offer considerable advantages over proton exchange membrane fuel cells (PEMFCs) in that the kinetics for oxygen reduction reaction (ORR) are greatly improved in alkaline media [1]. The improved kinetics of ORR in alkaline media thus allows for the use of PGM-Free catalysts in AEMFCs. Though there have been many efforts to develop PGM-Free cathode catalysts for AEMFCs, PGM-Free anode catalysts, with catalytic activity for HOR comparable to Pt, are still in the early stages of development [2]. The slow development of these AEMFC anode catalysts is largely due to the lack of compatible ionomers for anion exchange. However, recent development of anion exchange ionomers show great improvements over PEMFC ionomers, such as NAFION, in AEMFCs [3]. Carbon supported nickel has been shown to have high activity for HOR in AEMFCs, however the susceptibility of Ni to electrochemical oxidation, as well as the less than optimal hydrogen binding energy to the Ni active site, suggest there is further room for optimization of the Ni/C system [1]. Here, we have proposed to address these issues through alloying Ni with transition metals to tune the electronic environment of Ni, as well as to improve the corrosion resistance of Ni in alkaline media. For this project, catalysts are prepared by an incipient wetness method using the metal nitrates as catalyst precursors and KetjenblackÒ, DENKA BLACKÒ, graphene oxide (GO) and reduced graphene oxide (rGO) as support materials. GO and rGO have been prepared from Hummers’ method. In some cases, a sacrificial support method is also used to control the primary particle size of the NiM materials. Figure 1 shows the open circuit and close circuit polarization curves for NiMo/C with peak power density observed for HOR of ~ 120 mW/cm2, which is an encouraging result though not competitive with Pt or Pd. Therefore, our aim is to explore the role of the alloying metal (M = Mo, W, Cr, Co, Cu) as well as to investigate the role of the carbon support (ex: GO, rGO, N-doped rGO) on the kinetics of HOR in alkaline media on these NiM/C catalysts.

With the recent developments of high-performance anion-exchange membranes (AEM), there has been an increased interest towards studying various electrochemical reactions such as ethanol electrooxidation, hydrogen oxidation reactions and oxygen reduction reactions in AEM fuel cells (AEMFC). This increased attention has been attributed to the faster electro oxidation kinetics, increased stability and lower poisoning of the catalysts in alkaline media. And since AEMFCs are not limited to platinum - unlike in proton exchange membrane fuel cells (PEMFCs) with highly acidic environments - intensive efforts towards developing alternatives such as palladium (Pd) and Pd-based alloys are currently underway.1 , 2 Various studies have shown the enhanced stability and higher activities of Pd-based catalysts compared to Pt in alkaline medium using potentiodynamic and potentiostatic techniques. However, there are only a limited number of studies that have investigated the performance of Pd-based electrocatalysts in AEMFCs. Also, majority of these studies have demonstrated relatively low performances in AEMFCs, mainly due the complications associated with forming the triple-phase boundary (TPB) structure in the membrane layer, where reactions are taking place in the electrolyte, gaseous fuel and electrode interface. The density of the TPB, along with the intrinsic activities of the catalysts can play an important role in determining the overall performance of AEMFCs. Moreover, Pd-based are usually synthesized using surfactants, organic stabilizers or reducing agents, that can get adsorbed onto the surface of Pd and inhibit ionomer-catalyst-fuel interactions in the TPB. To mitigate the limitations associated with TPB structure and subpar catalyst activities, macroporous three-dimensional Graphene nanosheet (3D-GNS) supports with controlled morphologies and porosities were fabricated by utilizing silica sacrificial templates.3 The sacrificial templates were then etched to leave a network of porous channels within its matrix, and utilized as supports for Pd nanoparticles. The porous structure of these highly graphitized 3D-GNS supports can facilitate mass-transport kinetics by enabling the ionomer and polymer electrolyte getting the reactants to get catalyzed by Pd nanoparticles. Also, to enhance ionomer-nanoparticle interactions, the Pd nanoparticles of an average size of 3-5 nm were synthesized using a previously established surfactant-free soft alcohol reduction method.4 In this study, anion exchange catalyst-coated membranes (CCMs) were prepared using Pd nanoparticles supported on both commercial carbon blacks (Vulcan) and 3D-Graphene supports as both cathode and anode catalyst in H2/O2 fed AEMFCs. The Pd catalyst inks were prepared by mixing the dispersed Pd-catalyst in an optimized solution of isopropyl alcohol and quaternary ammonium-functionalized AS4 ionomer. The inks were then applied onto an anion exchange membrane (A201, Tokuyama) with an active area of 5 cm2. The CCMs was then hydrated in 0.5 M KOH for 24 hours, followed by rinsing in de-ionized water for 24 hours. It was then sandwiched between gas diffusion layers and annealed with gaskets by pressing under 500 psi for 5 minutes. The cell was then assembled and activated by operating at 0.3V at 60ºC for 10 minutes under humidified O2 and H2, followed by the measuring the polarization curves. Preliminary results show that Pd nanoparticles synthesized using surfactant-free method SARM and deposited on commercial carbon supports have and OCV of 0.95 V and a peak power output of 200 mWcm-2. These results already show the promising potential of using surfactant-free non-alloyed monometallic Pd nanoparticles. Further tests will also be performed to show the effect of porous 3D-Graphene supports towards modifying the TPB interphase and its effects on MEA performance in both Ethanol/O2 and H2/O2 fed AEMFCs. The results from this study will not only contribute towards the development of Pt-free oxidative and reductive electrocatalysts, but also lead to further advancements in AEMFC technology that will enable it to operate with other fuels such as methanol and hydrazine.

In this review, previous researches related to water transport in PEMFC are comprehensively reviewed. The state and transport mechanism of water in different components are elaborated in detail. The water transport in anion exchange membrane fuel cell (AEMFC) and the novel bipolar membrane fuel cell (BPMFC) are also discussed based on the cases in PEMFC. The water transport mechanism in AEMFC and BPMFC are similar to that of PEMFC, while the water management would be much difficult since the limitation properties of anion exchange membrane. In another hand, the difference between electrode reactions and membrane interface reactions for BPMFC make the transport of water more complicated. Fully understand the water transport in membrane electrode assembly is important in the develop of novel self-humidification fuel cells. As a result, the attractive cell configuration of BPMFC would make it a potential candidate for smart self-humidification fuel cells.

Since the 21st century, energy and environmental issues have become the focus of global attention. Traditional fossil energy resources such as oil and natural gas are drying up. Meanwhile, a large number of harmful gases and other pollutants would be produced in the use of traditional energy, which has a serious damage to the environment and climate. With the rapid increase of energy consumption and the need of environmental protection, the demand for clean and efficient energy is growing. Fuel cell (FC) is considered as one of the most promising energy conversion technologies that can replace conventional fossil fuels, and it is also an important choice in the use of hydrogen, methanol, ethanol and other renewable energy. As a new energy with great potential, FC can reduce the energy crisis and environmental pollution effectively by directly converting the chemical energy of the external input fuel into electrical energy and continuously supplying power to the outside. Ion exchange membrane (IEM) is an important component of FC, which is responsible for transferring ions and forming a complete FC circuit. According to the types of conducting ions, IEM can be divided into proton exchange membrane (PEM) and anion exchange membrane (AEM), which are applied to proton exchange membrane fuel cell (PEMFC) and alkaline anion exchange membrane fuel cell (AAEMFC), respectively. Compared with PEMFC, AAEMFC has the advantages of using non noble metal catalyst, high electrode reaction reactivity, and low fuel purity requirements and so on. However, the commercial AEM with organic cations often has low ionic conductivity and poor alkali and dimensional stability, which seriously hinders its development and application in AAEMFC. Therefore, it is urgent to design and develop new high-performance AEM materials. In order to improve the conductivity, alkali stability and dimensional stability of AEMs, a novel reactive bisphenol monomer with pendant dimethylphenoxybenzene group, 1,1-bis (4-hydroxyphenyl)-1-(4-(3,5-dimethylphenoxy) phenyl) phenyl-2,2,2-trifluoroethane ( 2 ), was synthesized based on molecular design using 4-fluoro-2,2,2-trifluoroacetophenone, 3,5-dimethylphenol and phenol as starting materials by a two-step organic reaction. Then, two series of poly(aryl ether sulfone) anion exchange membranes (2-PAES-QA- xx and 2-PAES-Im- xx ) with comb structure were prepared through aromatic nucleophilic copolycondensation, bromination and quaternization reaction based on monomer 2 . The structures of the active bisphenol monomer, the poly(aryl sulfone) containing methyl groups, the brominated poly(aryl ether sulfone)s and the ionized polymers were characterized systematically by nuclear magnetic resonance spectroscopy, respectively. The water uptake, swelling ratio, ionic conductivity, thermal stability, mechanical properties, and alkaline resistance stability of the prepared 2-PAES-QA- xx and 2-PAES-Im- xx membranes were studied in detail. The relationship between the structure and properties of different types of AEMs is further compared. The obtained AEMs showed good overall performance, and the OH– conductivity of these membranes at 60°C is 35.9–51.6 and 32.6–44.9 mS/cm, respectively. The IEC values of the representative 2-PAES-QA-60 and 2-PAES-Im-60 maintained at 79.7% and 88.5% of the initial values after immersion in 4 mol/L NaOH at 80°C for 336 h, respectively. This work provides a new strategy for the design and preparation of comb-type AEM materials.

Low cost and high durability are considered as the main challenges in mass scale commercialization of the low temperature fuel cells. Anion exchange membrane fuel cells (AEMFC’s) have attracted tremendous attention because of their promising characteristics to overcome some of the critical problems associated with proton exchange membrane fuel cells. The main advantages of AEMFC´s are possibility of using cheaper non-noble metal catalyst, lower crossover of cationic redox couples, facile reaction kinetics. In recent years, nitrogen-doping of carbon materials has been used to achieve active non-platinum catalyst.1,2 However it has been reported that the presence of transition metals such as Co or Fe can further enhances the electrocatalytic properties of N-doped carbons.3 The main goal of this study was to develop highly active transition metal-nitrogen co-doped catalyst as alternative cathode material to Pt/C in AMFC. A simple synthesis method was used to receive nitrogen doped multi-walled carbon nanotube supported CoCl2 catalyst material (Co/N-MWCNT). MWCNT treated in a concentrated HNO3-H2SO4 mixture were used as carbon support. MWCNTs were first dispersed in ethanol by sonication, after which dicyandiamide as the nitrogen source and Co salt were added along with a dispersing agent. The mixture was then heat-treated at 800 °C for 2 h in a tube furnace. Polished glassy carbon electrodes were modified with a dispersion containing the resulting materials and Tokuyama OH−ionomer AS-04. The rotating disk electrode (RDE) measurements were performed in 0.1 M KOH. The stability of the catalysts were also tested using RDE method. The structural and compositional properties of the catalyst material were defined by X-ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM). The oxygen reduction reaction (ORR) has been studied on Co/N/MWCNT electrocatalyst modified GC electrodes in 0.1 M KOH using the RDE method. The fuel cell performance of Co/N/MWCNT cathode catalyst material was investigated by fabricating membrane-electrode assemblies (MEAs) using Tokuyama membrane (# A201). The RDE results indicated excellent electrocatalytic properties of Co/N-MWCNT material toward oxygen electroreduction in alkaline media. The comparative study of Co/N-MWCNT with commercial Pt/C catalyst showed fair catalytic activity of our non-platinum catalyst in 0.1M KOH and significant enhancement of the ORR was observed in comparison to unmodified MWCNTs. The number of electrons transferred per oxygen molecule (n) at different potentials for the Co/N-MWCNT modified GC electrode was calculated from the KouteckyLevich equation. The value of n for the Co/N-MWCNT material was 4 over the whole range of potentials studied. The fuel cell performance was investigated with Co/N-MWCNT cathode catalyst and Tokuyama A201 anion exchange membrane. AEMFC performance was evaluated and compared at different temperatures up to 50 ⁰C. Maximum power density with H2/O2 gases at ambient pressure was ~115 mWcm-2. The fuel cell perfomance of the Co/N-MWCNT catalyst was also compared with the perfomance of the commercial Pt/C and cobalt phthalocyanine modified MWCNT catalysts (Fig.1).

Alkaline fuel cells have advantages over proton exchange membrane fuel cells both on cathode kinetics and ohmic polarization. The inherently faster kinetics of the oxygen reduction reaction in an alkaline fuel cell allows the use of Pt-free electrocatalysts that contributes directly to the low short-term costs and has environmental benefits as well. However, despite the early success in certain applications, alkaline fuel cells have an intrinsic obstruction of carbonation that is prohibitive for broad commercialization. This chapter describes the anion exchange membrane fuel cell technology. Using an anion exchange membrane instead of a liquid caustic alkali electrolyte in an alkaline fuel cell solves the problems of leakage, carbonation, precipitation of carbonate salts and prevents the gas electrode flooding, increasing the volumetric energy density. Recent progress on innovative selective catalysts has also been reviewed. It appears that the anion exchange membrane fuel cells have the potential to succeed in portable applications.

Anion exchange membrane fuel cells (AEMFCs) performance have significantly improved in the last decade (>1 W cm−2), and is now comparable with that of proton exchange membrane fuel cells (PEMFCs). At high current densities, issues in the catalyst layer (CL, composed of catalyst and ionomer), like oxygen transfer, water balance, and microstructural evolution, play important roles in the performance. In addition, CLs for AEMFCs have different requirements than for PEMFCs, such as chemical/physical stability, reaction mechanism, and mass transfer, because of different conductive media and pH environment. The anion exchange ionomer (AEI), which is the soluble or dispersed analogue of the anion exchange membrane (AEM), is required for hydroxide transport in the CL and is normally handled separately with the electrocatalyst during the electrode fabrication process. The importance of the AEI–catalyst interface in maximizing the utilization of electrocatalyst and fuel/oxygen transfer process must be carefully investigated. This review briefly covers new concepts in the complex AEMFC catalyst layer, before a detailed discussion on advances in CLs based on the design of AEIs and electrocatalysts. The importance of the structure–function relationship is highlighted with the aim of directing the further development of CLs for high‐performance AEMFC.

Fuel cell is environment-friendly power source which has high efficiency in generating electricity. Polymer electrolyte fuel cell uses hydrogen as a fuel that only produces water as byproduct which does not cause any pollution. Currently, commercialized Nafion-based polymer electrolyte membrane fuel cell (PEMFC) applied Pt/C as both cathode and anode catalyst which cause cost inefficiency in manufacturing fuel cell stack. Anion exchange membrane fuel cell (AEMFC) is being developed to combine advantages of both PEMFC and traditional alkaline fuel cell (AFC). By adopting solid membrane as electrolyte, leakage problem and insoluble salt precipitation could be solved. Furthermore, alkaline condition enhances oxygen reduction reaction (ORR) kinetics which obstructs cell power in PEMFC. However, stability of membrane is still in issue, and hydrogen oxidation reaction (HOR) kinetics are significantly diminished [1], which leads to higher Pt loading. This research is focusing at slow HOR kinetics and reducing catalyst cost by replacing Pt into non-precious metals such as transition metals. One of the well-known HOR catalyst for alkaline fuel cell is nickel. Several studies show nickel has catalytic activity of hydrogen oxidation in alkaline media [2,3], but it’s not enough to overcome precious metals such as platinum. Therefore, diverse researches tried to enhance activity of nickel by expanding surface area or doping other elements [4]. However, these catalytic activities were only tested in 6 M KOH, 60~80 ℃ condition, which is identical to real cell operating condition. NiMo catalyst was synthesized by electrodeposition method which is cost-effective way to produce. Nickel chloride is used for nickel source, and sodium molybdate worked as molybdenum source. Galvanostatic electrodeposition was applied to synthesize NiMo catalyst. Rotating disk electrode (RDE) was used to remove evolved hydrogen efficiently. HOR activity was measured in hydrogen saturated 0.1 M KOH solution. RDE was used to control diffusion with 1600 rpm speed. Experiment was held at room temperature. To remove capacitive current, steady state polarization method was applied for measuring HOR activity. Figure 1 shows HOR current of commercial Pt/C, electrodepositied NiMo, Ni. Adding small amount of Mo in Ni increases HOR current significantly. At overpotential of 20 mVRHE, Pt/C shows current density of 1.12 mA/cm2, where NiMo has 0.86 mA/cm2which is about 77% of Pt/C HOR activity. Reference [1] W. Sheng, et al., J. Electrochem. Soc. 157 (11), B1529 (2010) [2] T. Tomida, et al., J. Electrochem. Soc. 136 (11), 3296 (1989) [3] H. K. Lee, et al., Mat. Chem. Phys., 55, 89 (1998) [4] J. A. Linnekoski, J. Fuel Cell Sci. Tech., 4, 45 (2007) Figure 1

Anion exchange membrane fuel cells (AEMFCs) are the most promising low-temperature fuel cells and have received extensive attention. Compared to PEMFCs, the cost per unit of power can be significantly reduced for AEMFCs because, in theory, they allow the usage of non-precious metal catalysts and low-cost cell components. Owing to the development of advanced materials and performance improvement strategies, AEMFCs have achieved new records in both initial performance and durability. However, the high performance currently achieved is contingent on certain conditions, e. g., high Pt loading, large gas flowrates, and operation in pure O2 , which are far from practical applications. Therefore, the transition to commercially relevant performance and durability is the next goal of AEMFCs. This paper reviews the performance data of H2 -fueled AEMFCs since 2010 and summarizes possible performance optimization schemes, which can provide useful insights for developing next-generation AEMFCs.

The primary function of the ionomers that are incorporated into fuel cell electrode catalyst layers is to provide pathways for ion transport between the catalyst active sites and the electrolyte. This is influenced by many variables, including the ion‐exchange capacity, water uptake, and molecular weight. In anion exchange membrane fuel cells (AEMFCs), controlling ionomer water uptake is particularly important and tailoring this property in each electrode is an important consideration when looking to maximize cell performance. In this study, three poly(norbornene) tetrablock copolymer ionomers with a range of physical properties are synthesized and incorporated into AEMFC anode and cathode electrodes. Systematic electrode engineering with these ionomers allows the peak power density to be increased by 100% (1.6 W cm‐2 → 3.2 W cm‐2) and the current density at 0.2 V to be increased by 59% (5.9 A cm‐2 → 9.4 A cm‐2). Moreover, the top‐performing electrode configuration is tested in an operating AEMFC at the US Department of Energy defined current density of 600 mA cm‐2 for 2000 h, showing a record‐low voltage decay rate of 15.36 µV h‐1 – only 3.65% –a over 2000 h. This work sets a new bar for AEMFCs, reporting the best combination of performance and durability of any AEMFC to date.

Platinum group metal (PGM)‐free catalysts for oxygen reduction reaction have shown high oxygen reduction reaction activity in alkaline media. In order to further increase the power density of anion‐exchange membrane fuel cells (AEMFCs), PGM‐free catalysts need to have a high site density to reach high current densities. Herein, synthesis, characterization, and utilization of heat‐treated iron porphyrin aerogels are reported as cathode catalysts in AEMFCs. The heat treatment effect is thoroughly studied and characterized using several techniques, and the best performing aerogel is studied in AEMFC, showing excellent performance, reaching a peak power density of 580 mW cm−2 and a limiting current density of as high as 2.0 A cm−2, which can be considered the state‐of‐the‐art for PGM‐free based AEMFCs.

Much of the work on Anion Exchange Membrane Fuel Cells (AEMFCs) in recent years has focused on the development of new catalysts and membranes. Though this work is important, it has overlooked mass transport in these systems, which is equally critical to achieving high performance. This chapter provides an overview of aspects related to AEMFC water management and carbonation upon exposure to carbon dioxide. managing both of these are needed in order to achieve high performing fuel cells.

Fe/N/C is a promising electrocatalyst for oxygen reduction reaction (ORR). This type catalyst can perform in both acidic and alkaline media. In acidic media, the active sites of Fe/N/C can be corroded; however, in alkaline media, Fe/N/C can exhibit high stability. Therefore, it is promising to explore the applications of Fe/N/C catalyst in alkaline fuel cell. Herein, we will talk about our recent advances in preparation of Fe/N/C catalysts and the application of them in alkaline fuel cells: (1) By using 2-aminothiazole, a molecule containing both N and S atoms, we prepared S co-doped Fe/N/C catalyst with graphene nanosheets. In alkaline solution, this catalyst exhibited high ORR activity with half-wave potential of 0.926 V and mass activity of 0.56 A g-1 @ 1.0 V. Furthermore, the catalyst displayed excellent durability, and only lost 9% of initial activity after 100 h of durability test at 0.80 V. In alkaline anion exchange membrane fuel cell (AEMFC) test, the peak power density could reach 164 mW cm−2. (2) We used the unzipped carbon nanotubes as carbon support and melamine as nitrogen source, and prepared a Fe/N/C catalyst with high ORR activity in alkaline media. The edge sites of unzipped carbon nanotubes play a key role for high catalyst activity. (3) we explored a series of nitrogen source including binary polymer of melamine-terethalaldehyde, ternary polymer of cynuric acid, 2, 4-diamino-6-phenyl-1, 3, 5-triazine, and melamine. N-doped carbon nanotubes with encapsulated Fe nanoparticles were prepared. The catalyst exhibited considerably high ORR activity in alkaline solution. We further tested its performance in alkaline membrane direct ethanol fuel cell, and the peak power density was about 64 mW cm-2. These results demonstrated that Fe/N/C is a promising candidate for ORR electrocatalyst in alkaline fuel cell.