Development Of Polymer Electrolyte Membranes Research Articles

(Digital Presentation) The Utilization of Platinum Catalysts Deposited on Carbon Support Synthesized from Coffee Grounds in a Polymer Electrolyte Membrane Fuel Cell

Exploring alternative sources for platinum catalyst carbon support material is vital for the further development of polymer electrolyte membrane fuel cells (PEMFC).1 The support material and the method of depositing Pt nanoparticles are crucial for defining the catalytic properties of the catalyst. In this study, carbon support material, derived from coffee grounds was used in the preparation of Pt catalysts for PEMFC application. The carbon material was synthesized using ZnCl2 activated pyrolysis method2 and the Pt nanoparticles were deposited onto carbon support by two methods: using ethylene glycol3 or hydrogen4 as a reducing agent.The physical properties of the support material, as well as catalysts were analysed through thermogravimetric analysis (TGA), dynamic light scattering, X-ray diffraction (XRD), N2 sorption analysis and high-resolution scanning electron microscopy (HR-SEM) methods. The electrochemical activity, as well as the electrochemically active surface area (ECSA) of the catalysts were determined in a completed PEMFC. The properties and performance of catalysts synthesised were compared with the catalyst which was deposited onto commercial carbon (Ketjenblack, EC-300J).TGA displayed that carbon derived from coffee grounds contained 6.9 % of impurities by mass in the form of metal oxides and that the coffee carbon Pt catalyst contained 60 wt% of Pt. The Pt crystallite size was determined through XRD and it was 1.4 nm. HR-SEM analysis displayed that the average particle size of Pt nanoparticles on the coffee carbon catalyst was 4.7±2.5 nm. Results from N2 sorption analysis showed that all materials were micro-mesoporous, with coffee ground carbon having a specific surface area of 590 m2 g-1. The coffee carbon Pt catalyst produced smaller results of 370 m2 g-1 compared to the carbon support, due to the Pt nanoparticles depositing in the micropores, however still had a larger specific surface area than the commercial carbon catalyst with a specific surface area of 300 m2 g-1.Catalysts deposited on coffee ground carbon produced comparable electrochemical results to catalysts deposited on commercially available carbon. The coffee carbon catalyst produced a higher ECSA of 64 mPt 2 gPt -1, compared to the commercial carbon catalyst with an ECSA of 51 mPt 2 gPt -1. The current density of the Pt catalyst deposited onto coffee carbon was 0.68 A cm-2 at 670 mV, whilst in the same conditions commercial carbon peaked at 0.70 A cm-2. Both coffee and commercial carbon Pt catalysts produced similar power density maximums with the coffee Pt catalyst producing 0.56 W cm-2 and the commercial Pt catalyst producing 0.60 W cm-2.Physical and electrochemical characterizations displayed that higher ECSA values were strongly correlated to smaller Pt crystallite size. Other techniques to increase fuel cell performance were also experimented with, such as covering the gas diffusion layer with catalyst instead of Nafion membrane and adding additional Nafion layers, with both methods producing promising results.This study displays that there is a lot of potential in improving the catalytic performance of Pt catalysts by depositing on support materials derived from alternative sources. The methods of boosting PEMFC performance could be further investigated for catalysts deposited on different carbon supports. Acknowledgements This work was supported by the EU through the European Regional Development Fund TK141 “Advanced materials and high-technology devices for energy recuperation systems” (2014-2020.4.01.15-0011), Personal Research Grant PRG676 and by private limited company AuVe Tech LLTKT20148 “Production of Polymer Electrolyte Membrane Fuel Cells”. The SEM measurements were conducted using the NAMUR+ core facility funded by the Estonian Research Council (TT 13). References S. Shahgaldi and J. Hamelin, Carbon, 94, 705-728 (2015). M. Härmas, PhD thesis, University of Tartu, Tartu, Estonia (2020). Y. Shao, S. Zhang, R. Kou, X. Wang, C. Wang, S. Dai, V. Viswanathan, J. Liu, Y. Wang, Y. Lin, J. Power Sources 195, 1805-1811 (2010). Y. Zheng, Z. Dou, Y. Fang, M. Li, X. Wu, J. Zeng, Z. Hou, S. Liao, J. Power Sources, 306, 448-453 (2015).

Development of polymer electrolyte membrane based on poly(Vinyl Chloride)/graphene oxide modified with zirconium phosphate for fuel cell applications

The function of a membrane in the fuel cell is critical to its success. The major component of a direct methanol fuel cell (DMFC) is the proton exchange membrane (PEM) which must have proton conductivity, thermal stability, mechanical qualities, and low methanol permeability. In this study case, the film-forming and structural properties of Polyvinyl chloride (PVC) impelled us to employ them for developing polyelectrolyte membranes (PEMs). To functionalize the resultant PEMs, Graphene oxide (GO) and zirconium phosphate (ZrP) were incorporated into polyvinyl chloride in different proportions. The structural and physical properties of PVC/GO-ZrP membranes were investigated by using a variety of techniques instance, Fourier transform infrared spectroscopy (FTIR), Scanning electron microscope (SEM), Transmission electron microscope (TEM), Thermogravimetric analyzer (TGA), universal testing machine, and water contact angle meter. Furthermore, water uptake, Methanol uptake, and ion exchange capacity (IEC) were measured. The results demonstrated that the membranes developed have enough characteristics to be valid in DMFCs.

(Invited) Electro-Conversion of CO2 – a Technical and Economical Comparison between High Temperature and Low Temperature Processes

The booming technologies for the electrochemical conversion of CO2 aim to offer a carbon-neutral approach for industrial activities. The major greenhouse gas, CO2, can be reduced electrochemically with a low-carbon energy source in a highly effective manner. In this talk, we will provide a thorough technical and economical comparison between high temperature and low temperature processes. The thermodynamics of CO2 splitting, which is highly temperature-dependent, determines the energy requirement for the technologies. The development of polymer electrolyte membranes enables the low temperature electrochemical CO2 reduction in an aqueous system into various high-value products. High-temperature CO2 electrolysis based on solid oxide cells or molten carbonate cells reduces electricity cost and can be highly effective for CO production. Techno-economic assessment of these electrolysis techniques offers a comprehensive understanding on balancing efficiencies, economic cost and environmental benefits. The milestones on the materials/system development are proposed for high efficiency, low cost, high-value products and less negative environmental effects to move CO2 electrolysis technologies toward commercialization.

Defect stabilized Fe atom on porous BN sheet as a potential electrocatalyst for oxygen reduction reaction: A first-principles investigation

The slow kinetics of the cathodic oxygen reduction reduction (ORR) remain a significant issue in the development of polymer electrolyte membrane fuel cells (FCs). In this study, Fe-doped porous BN (p-BN) nanosheet is proposed as an efficient and noble-metal free electrocatalyst for the ORR process in FCs using first-principles calculations. The calculated formation energies show that the Fe atom is more stable on the p-BN with a boron vacancy than one with a nitrogen vacancy. The ORR process on this electrocatalyst begins with the cleavage of the OO bond of chemisorbed O2, followed by the hydrogenation of the separated O atoms to produce two water molecules. The rate-determining step in the ORR process is the formation of the second H2O molecule with an energy barrier of 1.12 eV. As a result, ORR prefers a direct four-electron route on the Fe-doped p-BN catalyst. Our findings can help in the design and manufacturing of novel electrocatalysts for ORRin FCs.

Development of polymer electrolyte membranes based on biodegradable polymer

Over the use of conventional liquid electrolytes, polymer based electrolytes have paid a special attention in the area of energy research mainly because of their flexibility and ease of availability. From the last few decades, non-degradable and synthetic polymers had been used as host polymers for the development of highly ionic conducting polymer electrolytes. From our earlier studies, different polymer electrolytes based on synthetic polymer such as polyethylene oxide (PEO) have also been studied with obtained conductivity values of the order of 10−7-10−4 S/cm. Three orders of increase in conductivity has been observed with the addition of additives such as plasticizer as well as nano filler and some of the data is represented in this paper. But in the present scenario, use of biodegradable polymer electrolytes is highly preferable over non-degradable polymer electrolytes because of their renewability and biocompatibility. Also, the use of blend and additives in the polymer electrolytes have become the most promising ways to improve the ion transport as well as electrochemical performance of polymer electrolytes. Polymer electrolytes based on specially the biodegradable polymer have been addressed to bring one step ahead to show the enhanced ionic conductivity, mechanical stability and improved interfacial stability towards electrode materials. Present paper highlights a review on the recent research efforts dedicated by researchers to understand the ion conduction mechanism in the modified polymer electrolytes as well as the usefulness of the biodegradable Polycaprolactone (PCL) as a host polymer in different polymer electrolytes.

Degradation Mechanisms of Supported Pt Nanocatalysts in Proton Exchange Membrane Fuel Cells: An Operando Study through Liquid Cell Transmission Electron Microscopy

Nanocatalysts’ degradation is a limiting factor for the development of polymer electrolyte membrane for fuel cells (PEMFCs). In this work, a dedicated sample holder has been used to mimic the cathode of a PEMFC at the earliest stages of the aging process, i.e., under accelerated stress test after up to 500 cycles. The mechanisms of surface area loss of supported platinum nanoparticles (Pt NPs) have been monitored in real-time and operando conditions by coupling liquid cell transmission electron microscopy (LTEM) to energy-filtered transmission electron microscopy (EFTEM), while cyclic voltammograms (CVs) were simultaneously recorded. The study has been performed using an ink made of a commercial catalyst (Tanaka-TEC10V50E) containing Pt NPs intended for automotive applications (3.0 ± 0.4 nm). First, a protocol has been set up to mitigate the electron-beam-induced radiolysis effects to a level that related artifacts are hindered or at least not appreciably detected during the duration of the experiment. At the same time, the resolution limit of the microscope has been pushed below 1 nm. Afterward, several degradation pathways were first identified and categorized and then correlated to the evolution of both the electrochemical active surface area (ECSA) and the Pt oxide reduction peak. We analyze reported evidence that the electrochemical aging favors the dissolution of the smaller Pt NPs. Dissolved cations are then observed to redispose onto larger supported Pt particles (electrochemical Ostwald ripening) or to be transported within the electrolyte, being either the aqueous acidic solution or the ionomer where they can precipitate (dissolution/precipitation process).

Impact of porous transport layer compression on hydrogen permeation in PEM water electrolysis

Gas permeation through a membrane electrode assembly (MEA) is an important issue in the development of polymer electrolyte membrane (PEM) water electrolyzers, because it can cause explosions and efficiency losses. The influence of operating pressure, temperature and MEA modifications on the permeation was already investigated. However, most of the studies pay no attention to the compression of the porous transport layer (PTL) of the MEA when assembling it in a test cell to carry out the experiments.This paper deals with the impact of the PTL compression on hydrogen permeation and cell voltage. Polarization, impedance and permeation measurements are used to demonstrate that the compression significantly affects the MEA's properties. Measurements show either a linear or nonlinear correlation between current density and hydrogen permeation, depending on the compression.The results indicate that the compression of the PTL must be taken into account for developing MEAs and comparing different permeation measurements.

Modelling Analysis of Platinum Dissolution in Polymer Electrolyte Membrane Fuel Cells with Gradient Cathode Catalyst Layers

Over the past decades, significant effort has been dedicated to the development of polymer electrolyte membrane fuel cells (PEMFC) with improved durability. To improve the durability of PEM fuel cells, the scientific focus has been to understand the factors that determine a PEM fuel cell’s lifetime, so that the lifetime can be increased without losing performance or increasing cost. Specifically, attention has been devoted to the stability of low Platinum cathode catalyst layers. Degradation of Platinum nanoparticles over carbon support is critical in consequence of several mechanisms, among which Platinum dissolution. As proposed in the literature, a possible strategy to mitigate Platinum dissolution consists in the development of catalyst layers with gradient properties [1]. In the present work, a theoretical analysis of Platinum dissolution is applied to the interpretation of degradation data recorded on catalyst-coated membranes (CCMs) fabricated by reactive spray deposition technique with 25 cm2 active area and low Pt loading 0.10 mg cm-2 for the cathode and 0.05 mg cm-2 for anode. The standard protocol defined by U.S. Department of Energy is used to subject the cells to accelerated stress test (AST) with triangle sweep cycles between 0.6 V and 1.0 V at 50 mVs−1 scan rate under inert atmosphere. The effect of aging on cell performance was monitored by measuring the electrocatalyst active surface (ECSA), hydrogen crossover, polarization curves and Electrochemical Impedance Spectroscopy (EIS) after 5000, 10,000, and 30,000 cycles. In order to get insight into the degradation process of cathode catalyst layer under accelerated durability testing, a 1D transient model referenced to the literature [2] has been calibrated and validated on a set of experimental data. The model solves the mass conservation equation for Platinum dissolved in the ionomer phase and a simple model for Platinum dissolution is proposed. The validity of the proposed model is discussed versus the experimental data that include in situ measurements collected on samples with different Platinum nanoparticle size (2nm, 3nm, 5nm) and ex situ data obtained from TEM observations. The evolution of catalyst active surface as predicted by the simulations reveals good consistency between model predictions and measurements, as reported in Fig. 1. It is concluded that the model captures the effect of particle size on nanoparticle stability and is thus used as a tool to analyze PEMFC durability in accelerated degradation tests. The model predicts the formation of a catalyst depleted zone, in consequence of the Platinum flux from the catalyst layer to the polymer membrane, in agreement with TEM observations. The model is later applied to the analysis of samples with gradient properties. Two sets of gradient catalyst layers have been analysed: materials with gradient in catalyst loading across the catalyst layer thickness; materials with gradient in Platinum particle size across the catalyst layer. In both cases the model can predict the trend of measured ECSA. The model predicts that the gradient materials show improved durability if they limit Platinum depletion in the region close to the polymer membrane. According to the model predictions, gradient samples with improved durability show higher content of Platinum catalyst retained in the region next to the membrane. Consistency with TEM observations obtained on gradient samples is discussed and some discrepancies are highlighted as a starting point to improve the model. Figure 1

Proton conducting membranes based on poly(acrylonitrile-co-styrene sulfonic acid) and imidazole

The development of polymer electrolyte membranes based on poly(acrylonitrile-co-styrene sulfonic acid) (PAN-co-PSSA) is reported. PAN-co-PSSA copolymers with two different copolymer compositions were synthesized via free radical polymerization, and confirmed by 1H NMR and elemental analysis. Homogeneous PAN-co-PSSA membranes were obtained via solvent cast method. PAN-co-PSSA membrane with the ratio of AN to SSA in the copolymer of 16:1 exhibited higher water uptake and IEC than that of 22:1. PAN-co-PSSA (16:1) was then doped with imidazole at molar ratios of 1:0.5, 1:1, and 1:2. Membrane functionalities were studied using FTIR. Thermal and mechanical properties were investigated using thermogravimetric analysis and dynamic mechanical analysis, respectively. All prepared membranes showed thermal stability of up to 180 °C, and showed superior mechanical property to that of Nafion® 117 within the studied temperature range. In addition, good oxidative stability was observed. Proton conductivity at room temperature was found to depend highly on relative humidity, and was enhanced through doping with imidazole. A maximum proton conductivity of 2.1 × 10−3 S/cm was achieved from membrane 1:2 saturated with water vapor. At higher temperatures (120–180 °C), proton conductivities of imidazole-doped membranes increased with increasing temperature and imidazole content.

Flatness-based feedforward control of polymer electrolyte membrane fuel cell gas conditioning system

Manufacturers of automotive applications rely on high-performance testing environments for the development of polymer electrolyte membrane fuel cell (PEMFC) technologies. The main component of a PEMFC testbed is the gas conditioning system, which controls the inlet gas temperature, stack pressure, relative humidity and mass flow of the gas at the inlet of the PEMFC stack. This paper presents a control concept for a highly dynamic PEMFC gas conditioning system. The main control challenge lies in the decoupling of the governing thermodynamic quantities. Therefore, the nonlinear control concept of exact input–output linearisation with an extended PID control structure is applied. Constraints on the actuators are incorporated by formulating the resulting control law as an optimisation problem. The robustness with respect to parameter uncertainties for the model is shown by investigating the trajectory tracking error of the disturbed system. Simulation results show an overall good performance for the trajectory tracking and demonstrate the robustness of the model against parameter uncertainties.

Analysis Process for Different Polymere Electrolyte Fuel Cell Stacks to Derive a Control Strategy Based on Impedance Data

AbstractTo further the development of polymer electrolyte membrane (PEM) fuel cells control strategies must be developed and optimized. In this study, an analysis process to derive a control strategy based on impedance data is developed and investigated. For this purpose an air cooled stack consisting of 12 cells and developed at Fraunhofer ISE was investigated. Impedance spectra were measured at different operating conditions to identify relevant frequencies at which an online control algorithm should be developed. A comparison of the impedance data between the analyzed stack and commercially available stacks of both air cooled and liquid cooled architectures suggest that the usable frequency ranges are independent of the stack. Hence, the presented analysis process is not limited to a specific stack design and yields a measure for the fuel cell's state of health that does not need information of a complete spectrum, but rather uses impedance data at a few discrete frequencies as control input.

A triazole-based polymer electrolyte membrane for fuel cells operated in a wide temperature range (25–150 °C) with little humidification

The development of polymer electrolyte membrane (PEM) fuel cells that can be operated over a wide temperature range without the need for humidification is highly desirable for vehicle applications to overcome the problems associated with CO poisoning and water management. Here we report a novel PEM based on 1H-1,2,4-triazole grafted polysiloxane doped with phosphoric acid and reinforced with porous expanded-polytetrafluoroethylene (ePTFE) film. Both bulk resistances and interfacial polarization resistances of the fuel cells based on this membrane were determined using impedance spectroscopy. Results indicate that the proton conductivities of the PEM have little dependence on operation temperature while the PEM fuel cells demonstrated good performance under very low humidity in a wide temperature range (from room temperature to more than 100 °C). The triazole-based new PEM may dramatically simplify the fuel-cell systems, offering great potential for mobile applications.

Recent Development of Polymer Electrolyte Membranes for Fuel Cells

Recent Development of Polymer Electrolyte Membranes for Fuel Cells

Electrochemical Behavior of Direct Methanol Fuel Cells Based on Acidic Silica - Sulfonated Polysulfone Composite Membranes

This paper reports on the research and development of polymer electrolyte membranes based on sulfonated polysulfone and acidic silica materials for application in DMFCs at different operating temperatures. The sulfonated polysulfone (SPSf) was synthesized using trimethyl silyl chlorosulfonate as the sulfonating agent, whereas silica was modified by treatment with chlorosulfonic acid at room temperature. The composite membranes based on sulfonated polysulfone and acidic silica were prepared by using a casting method from dimethylacetamide solutions. The membranes were characterized in terms of ion exchange capacity, methanol/water uptake, proton conductivity and DMFC performance. The membrane containing 10 wt.% of acidic silica showed a promising performance in DMFC investigations at temperatures comprised between 30°C and 60°C. A maximum power density of 60 mW cm-2 was obtained at 60°C feeding 1M methanol solution at the anode and dry air at the cathode, both at atmospheric pressure.

量子ビームを利用した燃料電池用高分子電解質膜の創製に関する研究

This paper describes the application of quantum beam-based technology to the development of polymer electrolyte membranes for fuel-cell applications. The γ-ray or electron-beam induced radiation grafting offers a way to prepare membranes; typically, the radical-initiated polymerization of a styrene or styrene-derivative monomer on a base polymer is followed by a sulfonation step. We previously obtained novel membranes using radiation- crosslinked fluoropolymers as the base material. Interestingly, combining this radiation-crosslinking process with the well-known chemical crosslinker method enabled us to prepare the “multiply-crosslinked” membranes, in which both the main and grafted chains have covalently bridged structures leading to a high durability. The bombardment of heavy ions accelerated to MeV or higher energies produces a continuous trail of excited and ionized molecules in polymers, which is known as a latent track. The approach using this ion-track technology is based on the chemical etching and/or modification of each track with diameters of tens to hundreds of nanometers. The resulting “nano-structure controlled” membrane was found to have perfect one-dimensional proton-conductive pathways parallel to its thickness direction, while, in contrast, other existing membranes mostly exhibited proton transport in the three-dimensional random media. We revealed the hierarchical structures of the membranes, ranging from nanometers to micrometers, by small-angle scattering experiments using a cold or thermal neutron beam. The information in such a wide length scale led to an insight into mass transport dynamics in the membrane from a molecular to macroscopic level, which can provide feedback for the reconsideration and optimization of the preparation procedure. As demonstrated above in our studies, it is important to understand that every quantum beam is different, thereby making the right beam choice.

Investigation of sulfonated polysulfone membranes as electrolyte in a passive-mode direct methanol fuel cell mini-stack

This paper reports on the development of polymer electrolyte membranes (PEMs) based on sulfonated polysulfone for application in a DMFC mini-stack operating at room temperature in passive mode. The sulfonated polysulfone (SPSf) with two degrees of sulfonation (57 and 66%) was synthesized by a well-known sulfonation process. SPSf membranes with different thicknesses were prepared and investigated. These membranes were characterized in terms of methanol/water uptake, proton conductivity, and fuel cell performance in a DMFC single cell and mini-stack operating at room temperature. The study addressed (a) control of the synthesis of sulfonated polysulfone, (b) optimization of the assembling procedure, (c) a short lifetime investigation and (d) a comparison of DMFC performance in active-mode operation vs. passive-mode operation. The best passive DMFC performance was 220 mW (average cell power density of about 19 mW cm −2), obtained with a thin SPSf membrane (70 μm) at room temperature, whereas the performance of the same membrane-based DMFC in active mode was 38 mW cm −2. The conductivity of this membrane, SPSf (IEC = 1.34 mequiv. g −1) was 2.8 × 10 −2 S cm −1. A preliminary short-term test (200 min) showed good stability during chrono-amperometry measurements.

Approaches and Recent Development of Polymer Electrolyte Membranes for Fuel Cells Operating above 100 °C

The state-of-the-art of polymer electrolyte membrane fuel cell (PEMFC) technology is based on perfluorosulfonic acid (PFSA) polymer membranes operating at a typical temperature of 80 °C. Some of the key issues and shortcomings of the PFSA-based PEMFC technology are briefly discussed. These include water management, CO poisoning, hydrogen, reformate and methanol as fuels, cooling, and heat recovery. As a means to solve these shortcomings, high-temperature polymer electrolyte membranes for operation above 100 °C are under active development. This treatise is devoted to a review of the area encompassing modified PFSA membranes, alternative sulfonated polymer and their composite membranes, and acid−base complex membranes. PFSA membranes have been modified by swelling with nonvolatile solvents and preparing composites with hydrophilic oxides and solid proton conductors. DMFC and H2/O2(air) cells based on modified PFSA membranes have been successfully operated at temperatures up to 120 °C under ambient pressure and up to 150 °C under 3−5 atm. Alternative polymers are selected from silicon- and fluorine-containing inorganic polymers or aromatic hydrocarbon polymers and functionalized by sulfonation. The sulfonated hydrocarbons and their inorganic composites are potentially promising for high-temperature operation. High conductivities have been obtained at temperatures up to 180 °C. Acid−base complex membranes constitute another class of electrolyte membranes. A high-temperature PEMFC based on H3PO4-doped PBI has been demonstrated for operation at temperatures up to 200 °C under ambient pressure. The advanced features include high CO tolerance, simple thermal and water management, and possible integration with the fuel processing unit.

The compression of hydrogen in an electrochemical cell based on a PE fuel cell design

The compression of gases in conventional compressors is often combined with low efficiency and the contamination of the compressed gases. In this paper, a system is described that uses an electrochemical cell for the compression of hydrogen. This electrochemical hydrogen compressor operates at lower hydrogen flux than mechanical hydrogen compressors. Further development of polymer electrolyte membrane (PEM) fuel cells afford a good prospect of realizing the electrochemical compression on a competitive basis. A specialized gas diffusion layer established the possibility to pressurize the cathode volume up to 54 bar. The ohmic resistance and pressure stability have been rescued by an improved membrane electrode assembly (MEA). A three cell stack on a laboratory scale has been designed. Data of single cell and stack experiments will be discussed in this paper. The advantages of the electrochemical system, apart from the efficiency, are: noiseless operation, purified hydrogen and simplicity of the system cooling.

Challenges for fuel cells in transport applications

The US Department of Energy (DOE) and the US automotive industry are working cooperatively under the auspices of the Partnership for a New Generation of Vehicles (PNGV) to develop a six-passenger automobile that can achieve up to 80 miles/gal. These partners are continuing to invest heavily in research and development of polymer electrolyte membrane (PEM) fuel cells as a clean and efficient alternative technology for transport applications. In the past few years, US automakers have made significant advances in fuel cell technology and have announced plans to put fuel cell vehicles on the market by 2004. DOE is working with industry suppliers to address some of the biggest remaining challenges, which include fuel processing and lowering the cost of fuel cell systems. The refueling infrastructure necessary to support fuel cell vehicles presents additional unresolved issues. This paper provides a status report on the PNGV program and provides an overview of the technical accomplishments and future plans of the DOE Fuel Cells for Transportation Program.

Development of polymer electrolyte membrane fuel cell stack

The proton exchange membrane fuel cell (PEMFC) is one of the strongest contenders as a power source for space, electric vehicle and domestic applications. Since 1988 intensive research is being carried out at our centre to develop PEMFCs. The main RandD activities are: (i) to develop a method for the electrode preparation (ii) to enhance platinum utilisation using low platinum loading and (iii) to design multicell stacks. The results of RandD development of the above activities are discussed in this paper.