Nano-electrocatalyst materials for low temperature fuel cells: A review (original) (raw)
Related papers
World Journal of Nano Science and Engineering, 2013
Highly-dispersed platinum and platinum-based catalysts on a conductive support are commonly used as electrode materials in low-temperature fuel cells, particularly the hydrogen PEMFC and the direct methanol PEMFC. The performance and durability/stability of these catalysts strongly depend on the characteristics of the support. Catalysts supported on high surface area carbon black are widely used in low-temperature fuel cells. However, the corrosion of carbon black has been recognized as one of major causes of performance degradation and durability issues of low-temperature fuel cells under high-potential conditions. So the need for alternative supports with outstanding physical and mechanical properties to carry out the successful reaction in catalyst layer and give a longer lifetime for the electrocatalysts is inevitable. The emergence of nanotechnology and development of nanostructure materials in recent years has opened up new avenues of materials development for low-temperature fuel cells. This paper presents the performance with a variety of carbon-based nanostructured materials such as carbon nanotubes (CNT), carbon nanofibers (CNF), carbon aerogels, nanoplates of graphene, etc. So the present paper provides an overview of these nanostructured materials as low-temperature fuel cell catalyst supports. The improved characteristics of the nanostructured supports with respect to commercially used carbon black (Vulcan XC-72) and their effect on the electrochemical activity are highlighted. Additionally, it reviews the literature on the synthesis of nanostructured-supported Pt electrocatalysts for proton exchange membrane (PEM) fuel cell catalyst loading reducing through the improvement of catalyst utilization and activity. The features of each synthetic method were also discussed based on the morphology of the synthesized catalysts.
Electrocatalysts for fuel cells
Catalysis Today, 1997
A brief description of the six main types of fuel cell which are currently under research and development is given. The discussion focuses on recent developments in the polymer electrolyte-based proton exchange membrane fuel cell with description of the limitations imposed by current electrocatalysts and the benefits offered by the development of improved materials. 0 1997 Elsevier Science B.V.
Development of tailored high-performance and durable electrocatalysts for advanced PEM fuel cells
International Journal of Hydrogen Energy, 2017
A family of novel carbon materials with intermediate surface area and varying morphology and surface chemistry were used to prepare Pt/C catalysts by two different preparation procedures; a chemical impregnation method and a microwave-assisted polyol method. The catalysts were thoroughly characterized, and their electrochemical performance and stability were investigated with rotating disc electrode (RDE) cyclic voltammetric (CV) measurements. The intermediate-surface-area carbon supports gave catalysts with much greater support stability than a widely used standard catalyst. The novel catalysts had lower electrochemical surface area than the reference, but their specific electrocatalytic activity towards the oxygen-reduction reaction (ORR) was much higher, and some of them also featured higher mass-specific ORR activity than the reference. The series of catalysts prepared by the microwave-assisted polyol method featured smaller Pt nanoparticles and higher activities than those prepared by impregnation. On the other hand, the impregnated catalysts showed better durability of the Pt particles. The most promising catalysts were selected and elaborated in further optimized preparation procedures to obtain quantities sufficient for their use in proton-exchange membrane fuel cells (PEMFCs).
Catalysis Today, 2012
The new catalytic electrodes and electrolytes for fuel cells and their synthesis methods have been described. The catalytic properties of the nanostructured membranes and electrodes are investigated both in vitro and in hydrogen-air fuel cell, in situ. The hybrid perfluorinated membranes, with the inorganic nanosize additives, were synthesized. An acceleration of electrode reactions during testing these membranes in fuel cell was observed. This shows the possibility of promotion effect of inorganic additives in the catalytic reaction of oxygen reduction at the electrode. The investigated membranes have enhanced transport properties, especially at low humidity. The nano-structured electrodes based on carbon nanofibers combined with gas diffusion layer have been developed. The high efficiency of carbon nanofibers grown in diffusion layer as catalyst support was shown; the efficiency of the prepared electrodes for oxygen electroreduction reaction is higher than efficiency of electrodes with the commercial catalyst E-TEK 20% Pt/C.
Electrochemical stability of carbon nanofibers in proton exchange membrane fuel cells
Electrochimica Acta, 2011
This fundamental study deals with the electrochemical stability of several non-conventional carbon based catalyst supports, intended for low temperature proton exchange membrane fuel cell (PEMFC) cathodes. Electrochemical surface oxidation of raw and functionalized carbon nanofibers, and carbon black for comparison, was studied following a potential step treatment at 25.0 • C in acid electrolyte, which mimics the operating conditions of low temperature PEMFCs. Surface oxidation was characterized using cyclic voltammetry, X-ray photoelectron spectroscopy (XPS), and contact angle measurements. Cyclic voltammograms clearly showed the presence of the hydroquinone/quinone couple. Furthermore, identification of carbonyl, ether, hydroxyl and carboxyl surface functional groups were made by deconvolution of the XPS spectra. The relative increase in surface oxides on carbon nanofibers during the electrochemical oxidation treatment is significantly smaller than that on carbon black. This suggests that carbon nanofibers are more resistant to the electrochemical corrosion than carbon black under the experimental conditions used in this work. This behaviour could be attributed to the differences found in the microstructure of both kinds of carbons. According to these results, carbon nanofibers possess a high potential as catalyst support to increase the durability of catalysts used in low temperature PEMFC applications.
Development of carbon nanotubes catalyst supported for alkaline fuel cell technology
Journal of Physics: Conference Series, 2019
Study of the development of an activated carbon nanotube catalyst for alkaline fuel cell technology. Through the prepared carbon nanotubes catalyst by an electrochemical deposition technique. Different analytical approaches such as X-ray diffraction (XRD) to determine the structural properties and Scanning Electron Microscope (SEM), were used to characterize, Mesh stainless steel catalyst substrate had an envelope structure and a large surface area. Voltages were also obtained at 1.83 V and current at 3.2 A of alkaline fuel cell. In addition, study the characterization of the electrochemical parameters.
Nanostructured Electrocatalysts for Advanced Applications in Fuel Cells
Energies
Nanostructured materials have gained much attention in recent engineering and material- science research due to their unique structural makeup, which stands them out from their bulk counterparts. Their novel properties of tiny-size structural elements (molecules or crystallites, clusters) of nanoscale dimensions (1 to 100 nm) make them a perfect material for energy applications. The recent keen interest in nanostructured materials research by academia and industrial experts arises from the unique variable characteristics of increased electrical and thermal conductivity. This occurs as nanostructured materials undergo a transient process from infinite-extended solid to a particle of ascertainable numbers of atoms. The commercial and energy sectors are very interested in developing and expanding simple synthetic pathways for nanostructured-electrocatalysts materials to aid in optimizing the number of active regions. Over the decades, various techniques have been put forward to design ...
Solid State Ionics, 2013
research. It gives fundamental definition for cell life time, capital cost, system stability and technique reliability. Loss of catalyst surface area due to corrosion of supporting material (normally carbon black) is one of the essential degradation mechanisms during cell operation. In this work, durability of carbon nanofibers (CNF) & carbon nanotubes (CNT) as alternative platinum catalyst supports for Proton Exchange Membrane Fuel Cells (PEMFCs) was assessed. Platinized CNF and CNT using a standard polyol method were prepared and fabricated as cathodes of Membrane Electrode Assemblies (MEA) for PEMFC. Both the catalysts as such and the MEAs made out of them were evaluated regarding to thermal and electrochemical stabilities using traditional carbon black (Vulcan XC72) as a reference. Thermal gravimetric analysis (TGA), cyclic voltammetry (CV), polarization curve and impedance spectroscopy were applied on the samples under accelerated stress conditions. The carbon nano-materials demonstrated better stability as a support for nano-sized platinum catalyst under PEMFC related operating conditions. Due to different morphology of the nano carbons compared to Vulcan XC 72 the electrode structures may still need optimization to improve the overall cell performance.
Studies on metal catalysts and carbon materials for fuel cell applications
2008
As a potential candidate for an environmentally benign and highly efficient electric power generation technology, proton exchange membrane fuel cells (PEMFC) are now attracting great interest for various applications. The main objective of this project has been to investigate the interfacial interaction of Pt nanoparticles with their carbon supports, so as to determine ways to optimise the catalyst electrode and to increase its catalytic activity, thereby enhancing PEM fuel cell performance. We first studied the interfacial interaction (leading to adhesion) of Pt nanoparticles evaporated onto untreated and Ar+-treated highly oriented pyrolytic graphite surfaces, with, respectively, low and high surface defect densities; HOPG was used as a model for carbon nanotubes (CNTs) and carbon fibers. We found that those Pt nanoparticles have very weak interactions with their pristine carbon material supports, with no evidence of compound formation between them. Our analysis, however, indicate...