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Showing 1 to 20 of 29 for “"Carbon support"”.
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Impact of carbon support chemistry, morphology, and structure on platinum catalyst durability for PEMFC applications
… changes in their porosity. Higher surface area carbons are also characterized by discontinuous graphite structures, making them more susceptible to oxidation than lower surface area carbon supports. It was also found that samples with higher microporosity (nanometers) were more stable than …
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In-situ investigation and mitigation of carbon support corrosion of cathode catalyst in PEM fuel cells
Carbon support corrosion (CSC) is one of the key factors causing cathode electrocatalyst (Pt/C) degradation in proton exchange membrane fuel cells (PEMFC). It is electrochemical oxidation and thus needs to be investigated in-situ with potential imposed. CSC was characterized in-situ and correlated …
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So<sub>2</sub> Adsorption On Carbon-Supported Pt Electrocatalyst
… was about 75 times smaller with only the carbon support. Amounts that exceed monolayer coverage on Pt correspond to a spillover on the carbon support. The spillover of SO<sub>2</sub> was examined by varying the Pt loading and particle size to distinguish desorption temperatures. X-ray …
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Evaluation of metal nitrides and borides as alternative electrocatalyst support materials for polymer electrolyte fuel cells
… stage. Poor durability is mainly attributed to carbon support corrosion during start-up and shut-down of the fuel cell. Corrosion of the electrocatalyst support materials has numerous adverse effects on the performance of the fuel cell, such as weakening of metal-support interaction which …
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Non-precious metal catalysts prepared by chemical functionalization of carbon surfaces.
… 1000°C) pyrolysis in an ammonia atmosphere of a carbon with adsorbed iron on the surface. Our approach to these catalysts employs surface chemical methods to more systematically synthesize the active site in order to better relate structure and activity. The current nitrogen compound of interest …
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Influence of particle size and morphology of Pt₃Co/C on the oxygen reduction reaction
… modified by varying the Pt/Pt₃Co loading on a carbon support. The catalysts were prepared using thermally induced chemical deposition. The support used was Vulcan-XC-72R. The effects of varying the metal loadings on the ORR was investigated. The loadings that were investigated were 20, 40, 60 …
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Anodic alcohol fuel cell reactions at platinum active sites on doped metal oxide supports
… via chemical reactions, which take place on the carbon supported platinum catalyst (Pt/C). As attractive as these devices may seem, their practicality is often limited by the functionality of the carbon support, which can be prone to corrosion. To limit the corrosion associated with a …
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Understanding the carbon morphology in sulfonated-silica ceramic carbon electrodes for the PEM fuel cell device
… linked to the use of Nafion® and the amount of carbon in the catalyst. In this work, 40 wt% Pt/C catalyst is used to obtain total electrode loadings as low as 0.2 mgPt cm-2, with the hypothesis of increased energy density while reducing catalyst layer thickness. This catalyst is used in …
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The hydrogenation of nitrobenzene over metal catalysts
… sensitive to the solvent and the nature of the carbon support. However more importantly it was shown that the first intermediate in Haber’s scheme, nitrosobenzene, could not act as an intermediate to nitrobenzene hydrogenation. As a result, a new reaction mechanism was proposed where the …
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Preparation and characterisation of inorganic nanostructured support materials for polymer electrolyte fuel cells
… and high costs associated with the current carbon supported platinum (Pt/C) catalysts. Carbon support corrosion and Pt dissolution/aggregation on the catalyst layer within the fuel cell have been confirmed as the major contributors to the degradation of the Pt/C (Shao, et al., 2007). …
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Preparation and Electrochemical Testing of Flexible Carbon Nanofiber Electrodes from Electrospinning
… conditions necessary for preparing flexible carbon nanofiber electrodes by electrospinning and to explore various applications for those electrodes. It was found that by varying only the relative humidity while electrospinning a poly(acrylonitrile) precursor, fragile or flexible freestanding …
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Development of oxorhenium complexes and bimetallic Re-Pd/C catalysts for perchlorate reduction in water
… palladium (Pd) nanoparticles on activated carbon support materials (Re-Pd/C). An oxorhenium(V) complex, Re(O)(hoz)2Cl (hoz = 2-(2’-hydroxyphenyl)-2-oxazoline), is synthesized as the precursor for a highly active metal center for oxygen atom transfer (OAT) reaction with ClO4-. Aqueous …
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Towards identifying platinum anchor sites on carbon via a model electrochemical system
The interaction between Pt and its carbon support was investigated by a model electrochemical system. This entailed aggressively oxidising a two-dimensional carbon substrate, i.e. highly orientated pyrolytic graphite (HOPG) and mirror finish graphite (MFG) quartz crystal, to incorporate oxygen …
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Functionalized carbon surfaces for clean electrochemical energy systems
… materials that implement platinum catalysts on a carbon support (Pt/C). The high cost and limited availability of platinum hinders the applicability of FCs. Nitrogen and metal-doped carbon supports have been investigated as a non-precious metal replacement for costly precious metal-based materials …
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Study of catalysts with high stability for proton exchange membrane fuel cells
… part of this work, stability of the catalyst support of PEMFC catalyst is investigated. Nanoscale platinum particles were loaded on two different kinds of carbon supports, nano graphene sheets and functionalized carbon black/graphene hybrid were developed by the liquid phase reaction. The …
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Model electrode structures for studies of electrocatalyst degradation
… of nanoparticles of Pt or Pt-based alloys on carbon supports. Understanding the role of the nanoparticle size and structure on the catalytic activity and degradation is needed to optimize the fuel cell performance and reduce the noble metal loading. Electrocatalyst degradation is believed to …
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Three-dimensional structure of a type III glutamine synthetase by single particle reconstruction
… with the larger ring in contact with the carbon support, accounted for this asymmetry, through partial staining. Hexameric views, with similar overall arrangement but larger size in comparison to GSI, were also observed. However, it was uncertain whether these were true hexamers resulting …
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The development and performance of anodic biofilms in microbial fuel cells
… the potential for successful scale-up as a low carbon technology. These systems utilize microorganisms residing in biofilms as biocatalytic agents in the conversion of reduced substrates to electrical energy. As such, it is important to understand how MFC anodic biofilms develop over time and …
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Low PGM PtCo alloy catalysts for low loading Polymer Electrolyte Membrane Fuel Cells
… characteristics (such as platinum loading, carbon to metal ratio and particle size), as well as fuel cell operating conditions. To establish an ideal low PGM MEA design, this thesis investigated two commercial PtCo catalysts (PtCoU30 and PtCoT50). Physical and electrochemical …
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Synthesis and characterization of cathode catalysts for use in direct methanol fuels cells
… and deposited Pt nanoparticles onto different carbon supports. Functionalization of some of the supports was also successfully carried out through acid oxidative treatment which introduced carboxylic acid and hydroxyl groups onto the surface of the supporting material, which was supported by …
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