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Strategies for Probing Nanometer-Scale Electrocatalysts: From Single Particles to Catalyst-Membrane Architectures

Description: The project primary objectives are to prepare and elucidate the promoting properties of materials that possess high activity for the conversion of hydrogen and related small molecules (water, oxygen, carbon monoxide and methanol) in polymer electrolyte fuel cells. One area of research has focused on the study of catalyst materials. Protocols were developed for probing the structure and benchmarking the activity of Pt and Pt bimetallic nanometer-scale catalyst against Pt single crystal electrode… more
Date: January 20, 2014
Creator: Korzeniewski, Carol
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

PEMFC MEA and System Design Considerations

Description: Proton exchange membrane fuel cells (PEMFCs) are being developed and sold commercially for multiple near term markets. Ballard Power Systems is focused on the near term markets of backup power, distributed generation, materials handling, and buses. Significant advances have been made in cost and durability of fuel cell products. Improved tolerance to a wide range of system operation and environmental noises will enable increased viability across a broad range of applications. In order to apply … more
Date: July 1, 2011
Creator: Knights, Shanna; Bashyam, Rajesh; He, Ping; Lauritzen, Michael; Startek, Cara; Colbow, Vesna et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Develpment of Higher Temperature Membrane and Electrode Assembly (MEA) for Proton Exchange Membrane Fuel Cell Devices

Description: Our work will fucus on developing higher temperature MEAs based on SPEKK polymer blends. Thse MEAs will be designed to operatre at 120 degrees C Higher temperatures, up to 200 degrees C will also be explored. This project will develop Nafion-free MEAs using only SPEKK blends in both membrane and catalytic layers.
Date: December 30, 2005
Creator: Susan Agro, Anthony DeCarmine, Shari Williams
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Highly Dispersed Alloy Catalyst for Durability

Description: Achieving DOE’s stated 5000-hr durability goal for light-duty vehicles by 2015 will require MEAs with characteristics that are beyond the current state of the art. Significant effort was placed on developing advanced durable cathode catalysts to arrive at the best possible electrode for high performance and durability, as well as developing manufacturing processes that yield significant cost benefit. Accordingly, the overall goal of this project was to develop and construct advanced … more
Date: January 8, 2013
Creator: Vivek S. Murthi (Primary Contact), Elise Izzo, Wu Bi, Sandra Guerrero and Lesia Protsailo
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Manufacturing Readiness Assessment for Fuel Cell Stacks and Systems for the Back-up Power and Material Handling Equipment Emerging Markets (Revised)

Description: This report details NREL's activity to address the need to understand the current status and associated risk levels of the polymer electrolyte membrane (PEM) fuel cell industry.
Date: February 1, 2010
Creator: Wheeler, D. & Ulsh, M.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Effect of Graphitic Content on Carbon Supported Catalyst Performance

Description: The effect of graphitic content on carbon supported platinum catalysts was investigated in order to investigate its influence on catalyst performance. Four catalysts of varying surface areas and graphitic content were analyzed using XPS, HREELS, and tested using RDE experiments. The catalysts were also heat treated at 150 C and 100%RH as means to uniformly age them. The heat treated samples were analyzed using the same methods to determine what changes had occurred due to this aging process. Wh… more
Date: July 1, 2011
Creator: Patel, A.; Artyushkova, K.; Atanassov, P.; Harvey, David; Dutta, M.; Colbow, V. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Calibration of a PEM detector with depth of interactionmeasurement

Description: We present an in situ calibration technique for the LBNL positron emission mammography (PEM) detector module that is capable of measuring depth of interaction (DOI). The detector module consists of 64LSO crystals coupled on one end to a single photomultiplier tube (PMT) and on the opposite end to a 64 pixel array of silicon photodiodes (PD). The PMT provides an accurate timing pulse, the PDs identify the crystal of interaction, the sum provides a total energy signal and the /splGamma/=PD/(PD+PM… more
Date: June 3, 2004
Creator: Wang, G.-C.; Huber, J. S.; Moses, W. W.; Choong, W. -S. & Maltz, J. S.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

PEM Degradation Investigation Final Technical Report

Description: This project conducted fundamental studies of PEM MEA degradation. Insights gained from these studies were disseminated to assist MEA manufacturers in understanding degradation mechanisms and work towards DOE 2010 fuel cell durability targets.
Date: October 18, 2010
Creator: Stevenson, Dan & Spangler, Lee H
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Development of the LBNL positron emission mammography camera

Description: We present the construction status of the LBNL Positron Emission Mammography (PEM) camera, which utilizes a PET detector module with depth of interaction measurement consisting of 64 LSO crystals (3x3x30 mm3) coupled on one end to a single photomultiplier tube (PMT) and on the opposite end to a 64 pixel array of silicon photodiodes (PDs). The PMT provides an accurate timing pulse, the PDs identify the crystal of interaction, the sum provides a total energy signal, and the PD/(PD+PMT) ratio dete… more
Date: December 19, 2002
Creator: Huber, Jennifer S.; Choong, Woon-Seng; Wang, Jimmy; Maltz, Jonathon S.; Qi, Jinyi; Mandelli, Emanuele et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

MEA Component Durability

Description: Membrane electrode assembly (MEA) lifetime of greater than 40,000 hours remains a goal of the fuel cell industry. However, there is a lack of fundamental understanding of the mechanisms of MEA degradation. Specifically, the relationship between component physical property changes and MEA performance decay has not been established. We report preliminary data relating changes in gas diffusion layer (GDL) physical properties to fuel cell performance decay.
Date: November 1, 2004
Creator: Frisk, J. W.; Hicks, M.T.; Atanasoski, R. T.; Boand, W. M.; Schmoeckel, A. K. & Kurkowski, M. J.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

PEM Fuel Cell Freeze Durability and Cold Start Project

Description: UTC has taken advantage of the unique water management opportunities inherent in micro-porous bipolar-plates to improve the cold-start performance of its polymer electrolyte fuel cells (PEFC). Diagnostic experiments were used to determine the limiting factors in micro-porous plate PEFC freeze performance and the causes of any performance decay. Alternative cell materials were evaluated for their freeze performance. Freeze-thaw cycling was also performed to determine micro-porous plate PEFC surv… more
Date: January 2, 2008
Creator: Patterson, T. & O'Neill, Jonathan
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Final Report - Advanced Cathode Catalysts and Supports for PEM Fuel Cells

Description: The principal objectives of the program were development of a durable, low cost, high performance cathode electrode (catalyst and support), that is fully integrated into a fuel cell membrane electrode assembly with gas diffusion media, fabricated by high volume capable processes, and is able to meet or exceed the 2015 DOE targets. Work completed in this contract was an extension of the developments under three preceding cooperative agreements/grants Nos. DE-FC-02-97EE50473, DE-FC-99EE50582 and … more
Date: September 28, 2012
Creator: Debe, Mark
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

New Accelerated Testing and Lifetime Modeling Methods Promise Faster Development of More Durable MEAs

Description: For the successful commercialization of fuel cell technology, it is imperative that membrane electrode assembly (MEA) durability is understood and quantified. MEA lifetimes of 40,000 hours remain a key target for stationary power applications. Since it is impractical to wait 40,000 hours for durability results, it is critical to learn as much information as possible in as short a time period as possible to determine if an MEA sample will survive past its lifetime target. Consequently, 3M has ut… more
Date: November 1, 2005
Creator: Pierpont, D. M.; Hicks, M. T.; Turner, P. L. & Watschke, T. M.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Development of Novel PEM Membrane and Multiphase CD Modeling of PEM Fuel Cell

Description: To understand heat and water management phenomena better within an operational proton exchange membrane fuel cell's (PEMFC) conditions, a three-dimensional, two-phase computational fluid dynamic (CFD) flow model has been developed and simulated for a complete PEMFC. Both liquid and gas phases are considered in the model by taking into account the gas flow, diffusion, charge transfer, change of phase, electro-osmosis, and electrochemical reactions to understand the overall dynamic behaviors of s… more
Date: December 30, 2009
Creator: Berry, K. J. & Das, Susanta
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Structural and Morphological Properties of Carbon Supports: Effect of Catalyst degradation, ECS Transactions 33(1), 425 (2010)

Description: The object of this work was to identify correlations between performance losses of Pt electrocatalysts on carbon support materials and the chemical and morphological parameters that describe them. Accelerated stress testing, with an upper potential of 1.2 V, was used to monitor changes to cathode properties, including kinetic performance and effective platinum surface area losses. The structure and chemical compositions were studied using X-ray Photoelectron Spectroscopy and Scanning Electron M… more
Date: April 1, 2011
Creator: Patel, A.; Artyushkova, K.; Atanassov, P.; Young, A.; Dutta, M.; Ahmad, Z. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Hydrogen Filling Station

Description: Hydrogen is an environmentally attractive transportation fuel that has the potential to displace fossil fuels. The Freedom CAR and Freedom FUEL initiatives emphasize the importance of hydrogen as a future transportation fuel. Presently, Las Vegas has one hydrogen fueling station powered by natural gas. However, the use of traditional sources of energy to produce hydrogen does not maximize the benefit. The hydrogen fueling station developed under this grant used electrolysis units and solar ener… more
Date: February 24, 2010
Creator: Boehm, Robert F; Sabacky, Bruce; Anderson II, Everett B; Haberman, David; Al-Hassin, Mowafak; He, Xiaoming et al.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

A mechanism for richer representation of videos for children: Calibrating calculated entropy to perceived entropy

Description: This study explores the use of the information theory entropy equation in representations of videos for children. The calculated rates of information in the videos are calibrated to the corresponding perceived rates of information as elicited from the twelve 7 to 10 year old girls who were shown video documents. Entropy measures are calculated for several video elements: set time, set incidence, verbal time, verbal incidence, set constraint, nonverbal dependence, and character appearance. As hy… more
Date: August 2001
Creator: Kearns, Jodi
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
open access

Final Project Report: Development of Micro-Structural Mitigation Strategies for PEM Fuel Cells: Morphological Simulations and Experimental Approaches

Description: The durability of PEM fuel cells is a primary requirement for large scale commercialization of these power systems in transportation and stationary market applications that target operational lifetimes of 5,000 hours and 40,000 hours by 2015, respectively. Key degradation modes contributing to fuel cell lifetime limitations have been largely associated with the platinum-based cathode catalyst layer. Furthermore, as fuel cells are driven to low cost materials and lower catalyst loadings in order… more
Date: June 28, 2013
Creator: Wessel, Silvia & Harvey, David
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Ex-Situ and in-Situ Stability Studies of PEM Fuel Cell Catalysts: The Effect of Carbon Type and Humidification on the Thermal Degradation of Carbon Supported Catalysts

Description: One of the most significant challenges for proton exchange membrane fuel cells in stationary power generation systems is lifetime, where 40,000 hours of operation with less than 10% decay in performance is desired. There are several different membrane electrode assembly (MEA) associated degradation mechanisms inhibiting MEAs from obtaining their desired lifetime targets. The focus of this research is on the loss of cathode surface area over time, which results in MEA performance losses, since M… more
Date: November 1, 2005
Creator: Haugen, G. M.; Stevens, D. A.; Hicks, M. T. & Dahn, J. R.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

High Temperature, Low Relative Humidity, Polymer-type Membranes Based on Disulfonated Poly(arylene ether) Block and Random Copolymers Optionally Incorporating Protonic Conducting Layered Water insoluble Zirconium Fillers

Description: Our research group has been engaged in the past few years in the synthesis of biphenol based partially disulfonated poly(arylene ether sulfone) random copolymers as potential PEMs. This series of polymers are named as BPSH-xx, where BP stands for biphenol, S stands for sulfonated, H stands for acidified and xx represents the degree of disulfonation. All of these sulfonated copolymers phase separate to form nano scale hydrophilic and hydrophobic morphological domains. The hydrophilic phase conta… more
Date: June 3, 2010
Creator: McGrath, James E. & Baird, Donald G.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Validation of an Integrated Hydrogen Energy Station

Description: This report presents the results of a 10-year project conducted by Air Products and Chemicals, Inc. (Air Products) to determine the feasibility of coproducing hydrogen with electricity. The primary objective was to demonstrate the technical and economic viability of a hydrogen energy station using a high-temperature fuel cell designed to produce power and hydrogen. This four-phase project had intermediate go/no-go decisions and the following specific goals: • Complete a technical ass… more
Date: October 26, 2012
Creator: Heydorn, Edward C.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Center for Intelligent Fuel Cell Materials Design

Description: The goal of this work was to develop a composite proton exchange membrane utilizing 1) readily available, low cost materials 2) readily modified and 3) easily processed to meet the chemical, mechanical and electrical requirements of high temperature PEM fuel cells. One of the primary goals was to produce a conducting polymer that met the criteria for strength, binding capability for additives, chemical stability, dimensional stability and good conductivity. In addition compatible, specialty nan… more
Date: August 26, 2008
Creator: Santurri, P.R., (Chemsultants International); Hartmann-Thompson, C. & Keinath, S.E. (Michigan Molecular Inst.)
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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