Comparative study on the resistance of different catalysts to electrochemical damage of fuel cells

This paper studies the catalytic performance and resistance to electrochemical damage of different catalysts in fuel cells by DFT calculations. The most commonly used platinum particle catalysts (Pt (111) surface) and three kinds of graphene-based platinum single-atom catalysts (G-N1-Pt, G-N2-Pt and G-N4-Pt) are selected as research objects. Based on Norskov's classical electrochemical theory, the step diagrams of hydrogen oxidation reaction (HOR) and oxygen reduction reaction (ORR) under the standard reaction conditions and the interference with the addition of SO₃⁻ groups are calculated. Combined with the actual adsorption situation in the intermediate steps of the reaction, the catalytic performance of the standard reaction and the catalytic performance under the interference of SO₃⁻ groups are compared. For HOR reaction and ORR reaction, the catalysts with the best catalytic ability and anti-interference ability are G-N1-Pt catalyst and G-N2-Pt catalyst, respectively. A catalyst selection principle that balances activation performance and anti-interference performance in fuel cells is proposed.     

Efficient tuning of the Pt nano-particle mono-dispersion on Vulcan XC-72R by selective pre-treatment and electrochemical evaluation of hydrogen oxidation and oxygen reduction reactions

The effect of chemical pre-treatment of the carbon support used for deposition of Pt nano-particles is reported. Data on particle size, distribution and their electocatalytic activity toward hydrogen oxidation reaction (HOR) and oxygen reduction reaction (ORR) are reported. Vulcan XC-72R carbon was pre-treated with 5% HNO₃, 0.07 M H₃PO₄, 0.2 M KOH and 10% H₂O₂. The properties of carbon supports were studied by N₂ adsorption and X-ray photoelectron spectroscopy (XPS). Chemical reduction with ethylene glycol (EG) was used to synthesize Pt on carbon supports and the differences in catalyst morphology were characterized using CO chemisorption, X-ray diffraction, energy dispersive X-ray analysis and transmission electron microscope techniques. The electrocatalytic activity of Pt/C catalysts toward HOR and ORR was examined by cyclic voltammetry (CV) on a rotating ring-disk electrode (RRDE) and compared with E-Tek Pt/C. The ORR was predominantly involved via four-electron process with the first electron transfer being the rate-determining step. However, the specific activity and mass activity were greatly influenced by the pre-treatment employed.     

Design of electrocatalysts with reduced Pt content supported on mesoporous NiWO4 and NiWO4-graphene nanoplatelets composite for oxygen reduction and hydrogen oxidation in acidic medium

Herein, a new direct synthesis route leading to a mesoporous NiWO₄ with crystalline framework and NiWO₄ - graphene nanoplatelets (GNP) composite is reported. Ni and W assembled into a mesoporous tungstate type of symmetry by co-precipitation synthesis route and its composite with GNP were used as supports for electrocatalysts, with reduced Pt content (8 wt.%), in oxygen reduction reaction (ORR) and hydrogen oxidation reaction (HOR) in acidic medium. A comprehensive assessment of the modifications related to the crystalline and porous structures, morphological aspects as well as the surface chemistry aiming to explain the electrochemical properties was performed. It was found that the presence of GNP during the synthesis process leads, mainly, to the enhanced growth of NiWO₄ nanocrystallites, as well as induces changes in the surface chemistry. The electrochemical results show that the introduction of GNPs into the NiWO₄ composite support leads to a significant improvement in the activity of the Pt electrocatalyst in ORR and HOR compared to both initial NiWO₄ and Pt/NiWO₄ samples, as well as mechanical mixtures of these catalysts with carbon. Mass activity for hydrogen oxidation, determined in a mixed kinetic-diffusion controlled region, obtained on the 8 wt.% Pt/NiWO₄-GNP catalyst was significantly higher compared to the commercial 20 wt.% Pt/C Quintech catalyst. Our comprehensive structural and surface chemistry assessments indicate this composite material as a viable electrocatalyst for PEMFCs using a broader type of fuels.     

High-surface-area organic matrix tris(aza)pentacene supported platinum nanostructures as selective electrocatalyst for hydrogen oxidation/evolution reaction and suppressive for oxygen reduction reaction

Developing a Pt-based electrocatalytic material able to selectively catalyze hydrogen oxidation (HOR) while supressing oxygen reduction (ORR) is beneficial for durability of the fuel cells. Namely, degradation of carbon supported Pt particles is dramatically influenced by the unwanted ORR enrolling at the anode due to the air penetration during start-up/shut-down events. We present an organic matrix tris(aza)pentacene (TAP), which belongs to π-functional materials with ladder-like conjugated nitrogen-containing units, as the support for Pt to form a “smart” fuel cell anode able to selectively catalyze HOR and to suppress ORR. “Switching-on/off” of the composite material activity is provided by reversible reduction/oxidation of the TAP in the low potential region which provokes TAP - H_xTAP transition. Conductivity of the reduced H_xTAP enables supported Pt particles to effectively run HOR. In contrast, restricted conductivity of oxidized TAP analogue leads to the substantial drop in the ORR activity with respect to benchmark Pt/C catalyst.     

A highly stable of tungsten doped Pr0.6Sr0.4Fe0.9W0.1O3-δ electrode for symmetric solid oxide fuel cells

In this work, a single perovskite Pr_0.6Sr_0.4Fe_0.9W_0.1O_3-δ (PSFW) for the electrode of SSOFCs is designed and successfully synthesized. The PSFW exhibits excellent structure stability in both reducing and oxidizing atmospheres and thermal compatibility with La_0.8Sr_0.2Ga_0.8Mg_0.2O_3-δ (LSGM) electrolyte. The area specific polarization resistances (ASRs) of PSFW under oxidizing and reducing atmospheres are only 0.086 and 0.215 Ω cm² at 800 °C, respectively. The symmetric electrode shows excellent electro-catalytic activity toward oxygen reduction reaction (ORR) and hydrogen oxidation reaction (HOR) and the corresponding impedance spectra under different hydrogen and oxygen partial pressures are further explored by distribution of relaxation times (DRT), which reveals that rate-limiting steps of HOR and ORR are the hydrogen adsorption/diffusion and oxygen diffusion, respectively. A LSGM electrolyte-supported cell with PSFW as symmetric electrodes displays the outstanding power density, considerable stability and reversibility, proving that the PSFW is a promising electrode material for symmetric solid oxide fuel cells.     

The effect of functionalised multi-walled carbon nanotubes in the hydrogen electrooxidation reaction in reactive currents impurified with CO

The present article investigates the tolerant effect exerted by a functionalised multi-walled carbon nanotube (MWCNT) support compared with the Vulcan XC-72 support for a nanoparticulate Pt catalyst. The negative effect produced in the hydrogen oxidation reaction (HOR) by the presence of a Pt contaminated with high CO coverage was analysed. This investigation was conducted using a rotating disk electrode (RDE) and a single cell with membrane electrode assemblies (MEAs) with loads of 0.3 mg Pt/cm² for the anode and 0.6 mg Pt/cm² for the cathode at various poisoning times. To this end, polarisation curves were performed, and electrochemical impedance spectroscopy (EIS) measurements were analysed. In addition, the recovery of the poisoning/de-poisoning process was studied. The –OH groups anchored to the MWCNT support exert a protective effect on the Pt nanoparticles, making the catalyst more efficient in a PEMFC fed with H₂ + CO.     

Kinetic study of the hydrogen oxidation reaction on sub-stoichiometric titanium oxide-supported platinum electrocatalyst in acid solution

The kinetics and mechanism of the hydrogen oxidation reaction were studied in 0.5 mol dm⁻³ HClO₄ solution on an electrode based on titanium oxide with Magneli phase structure-supported platinum electrocatalyst applied on rotation Au disk electrode. Pt catalyst was prepared by impregnation method from 2-propanol solution of Pt(NH₃)₂(NO₂)₂ and sub-stoichiometric titanium oxide powder. Sub-stiochiometric titanium oxide support was characterized by X-ray diffraction and BET techniques. The synthesized catalyst was analyzed by TEM technique. Based on Tafel-Heyrovsky-Volmer mechanism the corresponding kinetic equations were derived to describe the hydrogen oxidation current-potential behavior on RDE over the entire potential region. The polarization RDE curves were fitted with derived polarization equations according to proposed model. The fitting shows that the HOR on Pt proceeds most likely via the Tafel-Volmer (TV) pathway in the lower potential region, while the Heyrovsky-Volmer (HV) pathway is operative in the higher potential region. It is pointed out that Tafel equation that has been frequently used for the kinetics analysis in the HOR, can not reproduce the polarization curves measured with high mass-transport rates. Polarization measurements on RDE revealed that the Pt catalyst deposited on titanium suboxide support showed equal specific activity for the HOR compared to conventional carbon-supported Pt fuel cell catalyst.     

Electrostatic self-assembly of Pt nanoparticles on hexagonal tungsten oxide as an active CO-tolerant hydrogen oxidation electrocatalyst

Developing CO-tolerant electrocatalysts is of great importance for the practical use of proton exchange membrane fuel cells (PEMFCs) fed with reforming hydrogen. Transitional metal oxides are a class of promising component to (i) alleviate the CO adsorption on Pt and (ii) provide as a stabilized support for Pt nanoparticles. Herein, we developed an electrostatic assembly strategy to deposit Pt nanoparticles uniformly on the hexagonal tungsten oxides (hex-WO₃) modified by polyethleneimine (PEI). It is the first time employing hex-WO₃ with biomimetic proton channels and mixed ionic electronic conductivity as supports in PEMFCs. Also, this work is the first report using PEI as a linker to assemble Pt nanoparticles and metal oxide supports. The Pt/PEI-hex-WO₃ composites possess excellent dispersion of Pt nanoparticles with average size less than 3 nm even at Pt loadings as high as 40 wt%. The Pt/PEI-hex-WO₃ catalysts exhibit superior catalytic activity and electrochemical stability for the hydrogen electro-oxidation (HOR) in the presence of CO, and good PEMFC performance compared to the conventional carbon-supported Pt catalysts, attributed to the bifunctional mechanism and a strong metal-support interaction (SMSI).     

Effects of Pt loading in the anode on the durability of a membrane–electrode assembly for polymer electrolyte membrane fuel cells during startup/shutdown cycling

A polymer electrolyte membrane fuel cell (PEMFC) stack of a fuel cell vehicle (FCV) is inevitably exposed to reverse current conditions, which are formed by the oxygen reduction reaction (ORR) induced at the anode with a hydrogen/air boundary during startup/shutdown processes. With an increase in the reverse current, the degradation rate of the cathode that experiences a highly corrosive condition (locally high potential) increases. In this work, the anode Pt loading is decreased from 0.4 to 0.1 mg cm⁻² to decrease the reverse current. The decrease in the anode Pt loading is found to decrease the hydrogen oxidation rates (HOR) during normal operation, but this loading decrease barely affected the cell performance. However, a decrease in the anode Pt loading can significantly decrease the reverse current, leading to a diminished cathode degradation rate during startup/shutdown cycling. It is revealed by slow decreases in the cell performance (i–V curves) and electrochemical active surface area (EAS), and a slow increase in the charge-transfer resistance (R_ct), which can be attributed to corrosion of the carbon support and dissolution/migration/agglomeration of the platinum catalyst.     

Platinum nanoparticles decorated carbon nanofiber hybrids as highly active electrocatalysts for polymer electrolyte membrane fuel cells

Increasing the efficiency of electrocatalyst is the key demand for the polymer electrolyte membrane fuel cells (PEMFC). To address the activity and performance challenges of commercial electrocatalyst, Pt/C, we introduce a new hybrid catalyst support for Pt nanoparticles. In this regard, combining or mixing specific type of carbon-based supports is a feasible strategy to increase catalyst utilization and performance. In the current study, Pt nanoparticles (NPs) were decorated on a new hybrid network, comprising of carbon nanofiber (CNF) and carbon black (CB), by means of a facile and efficient microwave (MW) assisted reduction method. All synthesized electrocatalysts were characterized to elucidate chemical and morphological structures. Then, the hybrid electrocatalysts were utilized as hydrogen oxidation reaction (HOR) and oxygen reduction reaction (ORR) electrocatalysts and their electrocatalytic activities were investigated by using cyclic voltammetry (CV) and linear sweep voltammetry (LSV), respectively. We found that the hybridization of CNF with CB substantially improved not only the electrocatalytic activity but also the fuel cell performance, which can be attributed to a consecutive conductive network, in which CB acts as a spacer, and synergistic effects between the CNF and CB. The hybrid electrocatalyst (Pt/CNF-CB with 50:50 wt%) showed a superior activity toward HOR and ORR while also offering exceptional fuel cell performance. That hybrid possessed the highest electrochemically active surface area (ECSA) compared with Pt/CNF and Pt/CB. In addition, the mass activity (at 0.80 V vs RHE) of the Pt/CNF-CB (50:50 wt%) is about 3.3 and 3.5 times higher than that of Pt/CNF and Pt/CB, respectively. Furthermore, that hybrid electrocatalyst exhibited enhanced fuel cell performance with 907 mW.cm⁻¹ maximum power density. This work demonstrated that the CNF-CB supported Pt nanoparticles as electrocatalysts are extremely promising for fuel cell reactions.     

Preparation of Pt/graphene catalysts for polymer electrolyte membrane fuel cells by strong electrostatic adsorption technique

The Pt/graphene catalysts were prepared by using strong electrostatic adsorption (SEA) technique for polymer electrolyte membrane fuel cell (PEMFC). The pH shift was considered and the point of zero charge (PZC) of graphene was acquired at pH about 5.2. Due to the mid-to-low PZC, the cationic precursor (i.e., platinum tetra-ammine ([NH₃)₄ Pt]²⁺ or PTA) was chosen. After graphene surface was treated to be anionic substrate, the PTA was added and adsorbed onto the graphene by electrostatic force. Pt metals between before and after adsorption were determined by inductively coupled plasma spectroscopy (ICP) in order to consider Pt percent weight. After reduction in hydrogen environment, Pt/graphene catalysts were made. The second adsorption including the reduction was repeated in order to obtain the high Pt percentage such as 21.5%wt. The average particle sizes (ca. 2.2 nm) and distribution of Pt were inspected using transmission electron microscopy (TEM), where the crystalline structures were verified by X-Ray diffraction (XRD). Electrochemical properties were tested using cyclic voltammetry (CV) and the accelerated durability test (ADT) was also carried out. The oxygen reduction reaction (ORR) was also carried out, where the specific activity and mass activity were examined. It was observed from ADT that mass activity lost about 33%. Furthermore, the ORR was performed to verify the first order reaction, as well as to determine the mechanism path way for four electron transfer. Moreover, the kinetic constant of the ORR was also estimated.     

Tailoring the hydrophilic and hydrophobic reaction fields of the electrode interface on single crystal Pt electrodes for hydrogen evolution/oxidation reactions

Interfacial hydrophobic/hydrophilic reaction fields significantly affect various reactions at the electrode surface. The hydrogen evolution reaction (HER) and the hydrogen oxidation reaction (HOR) have been investigated on single crystal Pt electrodes modified with hydrophobic/hydrophilic cations and anion-exchange copolymers in alkaline solutions. In alkali metal hydroxide solutions, Pt (110) exhibits the highest HER/HOR activity in the low-index planes of Pt. On the low-index planes of Pt, the hydrophilicity of the alkali metal cation in the supporting electrolyte activates the HER/HOR depending on its hydration energy. Hydrophilic cations at the interface facilitate the extraction of hydrogen from the hydrated water. The modification of anion-exchange copolymers with a hydrophobic skeleton on Pt (110) further enhanced the HER/HOR activity. The hydrogen bonding network formed around the hydrophobic species facilitated the mobility of water molecules and the OH⁻ as the reactant/product of the HER/HOR. Appropriately forming hydrophilic and hydrophobic reaction fields at the interface improved the HER/HOR activity.     

Polybenzimidazole-membrane-based PEM fuel cell in the temperature range of 120–200 °C

Phosphoric acid-doped polybenzimidazole-membrane-based PEM fuel cells were tested in the temperature range of 120–200 °C, with ambient backpressure and 0% RH. AC impedance spectroscopy, surface cyclic voltammetry and fuel cell performance simulation were used to obtain the exchange current densities for the cathodic oxygen reduction reaction (ORR) and anodic hydrogen oxidation reaction (HOR) on platinum-based catalysts at such high temperatures. The activation energies for ORR, HOR and membrane conductivity were also obtained separately. The results showed that temperature significantly affects the charger transfer and gas (O₂ and H₂) diffusion resistances. The effect of O₂ stoichiometry (ST_air) on fuel cell performance was also investigated. Increasing ST_air can effectively increase the O₂ partial pressure in the feed air, leading to improvements in both the thermodynamics and the kinetics of the fuel cell reactions. In addition, it was observed that increasing ST_air could also improve the gas diffusion processes.     

Binary CuPt alloy nanoparticles assembled on reduced graphene oxide-carbon black hybrid as efficient and cost-effective electrocatalyst for PEMFC

Addressed herein is the synthesis of binary CuPt alloy nanoparticles (NPs), their assembly on reduced graphene oxide (rGO), Vulcan XC72 (VC) and their hybrid (rGO-VC) to be utilized as electrocatalysts for fuel cell reactions (HOR and ORR) in acidic medium and PEMFC tests. The synthesis of nearly-monodisperse Cu₄₅Pt₅₅ alloy NPs was achieved by using a chemical reduction route comprising the reduction of commercially available metal precursors in a hot surfactant solution. As-synthesized Cu₄₅Pt₅₅ alloy NPs were then assembled on three support materials, namely rGO, VC and rGO-VC) via liquid phase self-assembly method. After the characterization, the electrocatalysts were prepared by mixing the yielded materials with Nafion and their electrocatalysis performance was investigated by studying CV and LSV for HOR and ORR in acidic medium. Among the three electrocatalysts tested, Cu₄₅Pt₅₅/rGO-VC hybrid showed the highest catalytic activity with ECSA of 119 m² g⁻¹ and mass activity of 165 mA mg⁻¹_Pt. After the evaluation of electrochemical performance of the three prepared electrocatalysts, their performance was then evaluated in fuel cell conditions. In similar to electrochemical activities, the Cu₄₅Pt₅₅/rGO-VC hybrid electrocatalyst showed a superior fuel cell performance and power output by providing a maximum power of 480 mW cm⁻² with a relatively low Pt loading (0.28 mg cm⁻²). Additionally, the Cu₄₅Pt₅₅/rGO-VC hybrid electrocatalyst exhibited substantially better activity as compared to Pt/rGO-VC electrocatalyst. Therefore, the present study confirmed that alloying Pt with Cu enhances the catalytic activity of Pt metal along with the help of beneficial features of rGO-VC hybrid support material. It should be noted that this is the first example of studying PEMFC performance of CuPt alloy NPs supported on rGO, VC and rGO-VC hybrid.     

Electrochemical performance and distribution of relaxation times analysis of tungsten stabilized La0·5Sr0·5Fe0·9W0·1O3-δ electrode for symmetric solid oxide fuel cells

W-doped La_0·5Sr_0·5Fe_0·9W_0·1O_3-δ (LSFW) was prepared and evaluated as a symmetric electrode for solid oxide fuel cells (SSOFCs). Phase and structural stability of LSFW under both reducing and oxidizing atmospheres was studied. The oxygen reduction reaction (ORR) and hydrogen oxidation reaction (HOR) mechanisms were investigated by using electrochemical impedance spectra (EIS) and distribution of relaxation times (DRT). Electrode polarization resistance (R_p) of LSFW are 0.08 and 0.16 Ω cm² in air and wet hydrogen at 800 °C, respectively. DRT results indicate that the rate-limiting step of LSFW at 800 °C in cathodic conditions and anodic conditions are related to oxygen diffusion and hydrogen adsorption/diffusion, respectively. A La_0·8Sr_0.2Ga_0.8Mg_0·2O_3-δ (LSGM) electrolyte-supported single cell using LSFW electrodes shows a maximum power density of 617.3 mW cm⁻² at 800 °C with considerable stability and reversibility, which enables LSFW a promising SOFCs symmetric electrode material.     

Durability of PEM fuel cell electrocatalysts prepared by microwave irradiation technique

In this study, the durability of the PEM fuel cell electrocatalysts was investigated by using cyclic voltammetry (CV) and rotating disk electrode (RDE) techniques. Accelerated degradation tests (ADTs) were applied to the commercial catalysts and the electrocatalysts prepared by microwave irradiation technique in order to determine the platinum dissolution/agglomeration and carbon corrosion characteristics. The parameters examined for the commercial catalysts were carbon to Nafion (C/N) ratio in the catalyst ink and Pt loading over the carbon support. The parameters examined for the home-made catalysts were the conditions altered in the microwave environment including the base concentration and microwave duration. The hydrogen oxidation reaction (HOR) and oxygen reduction reactions (ORR) were examined before and after ADTs. The results showed that the catalyst properties differently affect the HOR and ORR activities of the catalysts before and after ADTs.     

Pt/C catalyst impregnated with tungsten-oxide – Hydrogen oxidation reaction vs. CO tolerance

Hydrogen Oxidation Reaction (HOR) is anode reaction in Proton exchange membrane fuel cells (PEMFCs) and it has very fast kinetics. However, the purity of fuel (H₂) is very important and can slow down HOR kinetics, affecting the overall PEMFC performance. The performance of commercial Pt/C catalyst impregnated with WO_x, as a catalyst for HOR, was investigated using a set of electrochemical methods (cyclic voltammetry, linear scan voltammetry and rotating disk electrode voltammetry). In order to deepen the understanding how WO_x species can contribute CO tolerance of Pt/C, a particular attention was paid to CO poisoning. In the absence of CO, HOR is under diffusion limitations and HOR kinetics is not affected by WO_x species. Appreciable HOR current on the electrodes pre-saturated with CO_ads at potentials above 0.3 V vs. RHE, which is not observed for pure Pt/C, was discussed in details. HOR liming diffusion currents for higher concentrations of W are reached at high anodic potentials. The obtained results were explained by donation of OH_ads by WO_x phase for CO_ads removal in the mid potential region and reduced reactivity of Pt surface sites in the vicinity of the Pt|WO_x interface. The obtained results can provide guidelines for development of novel CO tolerant PEMFC anode catalysts.     

Palladium-based electrocatalysts for hydrogen oxidation and oxygen reduction reactions

Fuel cells, especially low temperature fuel cells are clean energy devices that are expected to help address the energy and environmental problems that have become prevalent in our society. Platinum-based electrocatalysts are usually used as the electrocatalysts for both the anode (hydrogen oxidation) and cathode (oxygen reduction) reactions. The high cost and limited resources of this precious metal hinder the commercialization of fuel cells. Recent efforts have focused on the discovery of palladium-based electrocatalysts with little or no platinum for hydrogen oxidation reaction (HOR) and oxygen reduction reaction (ORR). This paper overviews the recent progress of electrocatalysis of palladium-based materials including both extended surfaces and nanostructured ones for HOR and ORR. The properties of CO and methanol tolerances of palladium-based electrocatalysts are also summarized.     

In-situ investigation on the CO tolerance of carbon supported Pd–Pt electrocatalysts with low Pt content by electrochemical impedance spectroscopy

Carbon supported Pd–Pt electrocatalysts (Pd–Pt/C) with low Pt content were investigated in proton exchange membrane fuel cells (PEMFCs) with pure H₂ and CO/H₂ as the feeding fuels, respectively. The Pd–Pt/C catalysts showed high activity for hydrogen oxidation reaction (HOR) and improved CO tolerance. Electrochemical impedance spectroscopy (EIS) was employed to probe the in-situ information of the improved CO tolerance. The dependence of Nyquist plots and Bode plots on current density and feeding gas was investigated in low polarization region. The results of EIS analysis indicated that the improved CO tolerance of Pd–Pt/C catalysts can be attributed to the lower coverage of CO on the Pd–Pt bimetal than that on the pure Pt.     

1D-2D integrated hybrid carbon nanostructure supported bimetallic alloy catalyst for ethanol oxidation and oxygen reduction reactions

Herein, 1-D carbon nanotubes and 2-D graphene hybrid carbon hetero-structure is employed as the catalyst support material for low temperature fuel cell. Partial unraveling of carbon nanotubes results in 1D-2D hybrid hetero-structure with enhanced surface area, while the intact inner tubes result in good electrical conductivity. Platinum-tin alloy decorated on partially exfoliated carbon nanotubes (Pt–Sn/PCNT) were prepared by ethylene glycol reduction method and investigated its electrocatalytic activity towards ethanol oxidation reaction (EOR) for direct ethanol fuel cell (DEFC) and oxygen reduction reaction (ORR) for hydrogen fuelled polymer electrolyte membrane fuel cell (PEMFC). Along with the intrinsic properties of carbon nanotubes, PCNT provides more anchoring sites, thereby facilitates complete utilization of catalysts. The electrochemical EOR studies reveal that Pt–Sn/PCNT has better tolerance to the accumulation of intermediate species than Pt–Sn/CNT. Besides, as-synthesized electrocatalysts exhibit good ORR activity with four-electron pathway. The enhanced EOR and ORR activity of as prepared electrocatalysts is attributed to the high dispersion of catalyst nanoparticles on PCNT along with the inhibition of production of intermediate species on the Pt surface by alloying. Further, the practical suitability of PCNT supported Pt–Sn nanocatalysts as EOR and ORR electrocatalysts has been examined by performing the full fuel cell measurements.