Search Results

Advanced search parameters have been applied.
open access

Proton exchange membrane fuel cells with chromium nitridenanocrystals as electrocatalysts

Description: Polymer electrolyte membrane fuel cells (PEMFCs) are energy conversion devices that produce electricity from a supply of fuel, such as hydrogen. One of the major challenges in achieving efficient energy conversion is the development of cost-effective materials that can act as electrocatalysts for PEMFCs. In this letter, we demonstrate that, instead of conventional noble metals, such as platinum, chromium nitride nanocrystals of fcc structure exhibit attractive catalytic activity for PEMFCs. Dev… more
Date: July 1, 2007
Creator: Zhong, Hexiang; Chen, Xiaobo; Zhang, Huamin; Wang, Meiri & Mao,Samuel S.
Partner: UNT Libraries Government Documents Department
open access

IGR NO{sub x}/SO{sub x} control technology. Quarterly report January 1, 1995--February 28, 1995

Description: During the first quarter of 1994, work was concentrated on improving the power efficiency of the IGR NOx/SOx control technology. IGR continued to work on its electrocatalyst materials to improve the electrical efficiency required for economical NOx/SOx destruction. In addition IGR continued to modify the electrocatalyst/electrolyte interface with the goal of improving selectivity and current efficiency. Specifically, work concentrated on changing the solid state defect concentration in the soli… more
Date: January 1, 1994
Partner: UNT Libraries Government Documents Department
open access

COMPONENT DEVELOPMENT NEEDS FOR THE HYBRID SULFUR ELECTROLYZER

Description: Fiscal year 2008 studies in electrolyzer component development have focused on the characterization of membrane electrode assemblies (MEA) after performance tests in the single cell electrolyzer, evaluation of electrocatalysts and membranes using a small scale electrolyzer and evaluating the contribution of individual cell components to the overall electrochemical performance. Scanning electron microscopic (SEM) studies of samples taken from MEAs testing in the SRNL single cell electrolyzer tes… more
Date: May 30, 2008
Creator: Hobbs, D; Hector Colon-Mercado, H & Elvington, Mark C.
Partner: UNT Libraries Government Documents Department
open access

SYNTHESIS AND CHARACTERIZATION OF CO- AND H{sub 2}S-TOLERANT ELECTROCATALYSTS FOR PEM FUEL CELL

Description: The present state-of-art Proton Exchange Membrane Fuel Cell (PEMFC) technology is based on platinum (Pt) as a catalyst for both the fuel (anode) and air (cathode) electrodes. This catalyst is highly active but susceptible to poisoning by CO, which may be present in the H{sub 2}-fuel used or may be introduced during the fuel processing. Presence of trace amount of CO and H{sub 2}S in the H{sub 2}-fuel poisons the anode irreversibly and decreases the performance of the PEMFCs. In an effort to red… more
Date: April 5, 2005
Creator: Ilias, Shamsuddin
Partner: UNT Libraries Government Documents Department
open access

SYNTHESIS AND CHARACTERIZATION OF CO-AND H2S-TOLERANT ELECTROCATALYSTS FOR PEM FUEL CELL

Description: The present state-of-art Proton Exchange Membrane Fuel Cell (PEMFC) technology is based on platinum (Pt) as a catalyst for both the fuel (anode) and air (cathode) electrodes. This catalyst is highly active but susceptible to poisoning by CO, which may be present in the H{sub 2}-fuel used or may be introduced during the fuel processing. Presence of trace amount of CO and H{sub 2}S in the H{sub 2}-fuel poisons the anode irreversibly and decreases the performance of the PEMFCs. In an effort to red… more
Date: March 31, 2004
Creator: Ilias, Shamsuddin
Partner: UNT Libraries Government Documents Department
open access

SYNTHESIS AND CHARACTERIZATION OF CO-AND H2S-TOLERANT ELECTROCATALYSTS FOR PEM FUEL CELL

Description: The present state-of-art Proton Exchange Membrane Fuel Cell (PEMFC) technology is based on platinum (Pt) as a catalyst for both the fuel (anode) and air (cathode) electrodes. This catalyst is highly active but susceptible to poisoning by CO, which may be present in the H{sub 2}-fuel used or may be introduced during the fuel processing. Presence of trace amount of CO and H{sub 2}S in the H{sub 2}-fuel poisons the anode irreversibly and decreases the performance of the PEMFCs. In an effort to red… more
Date: March 29, 2005
Creator: Ilias, Shamsuddin
Partner: UNT Libraries Government Documents Department
open access

Application of an Electrochemical Quartz Crystal Microbalance to the study of electrocatalytic films

Description: The EQCM was used to study the deposition and composition of electrodeposited pure PbO{sub 2} and Bi-doped PbO{sub 2} active toward anodic oxygen-transfer reactions. Within the doped films, Bi is incorporated as Bi{sup +5} in the form of BiO{sub 2}A, where A is ClO{sub 4}{sup {minus}} or NO{sub 3}{sup {minus}}. For deposition of these 2 materials, changes in hydration between the Au oxide and the depositing film resulted in higher mass-to-charge ratios. XRD and XPS were used to study the films;… more
Date: September 1, 1993
Creator: Gordon, J. S., Jr.
Partner: UNT Libraries Government Documents Department
open access

Anodic oxygen-transfer electrocatalysis at iron-doped lead dioxide electrodes

Description: The research illustrated in this thesis was performed under the guidance of Professor Dennis C. Johnson beginning in March 1987. Chapter 2 concentrates on the development and electrocatalytic properties of iron-doped {beta}-PbO{sub 2} films on noble-metal substrates. Chapter 3 focuses attention on the preparation and characterization of iron-doped {beta}-PbO{sub 2} films on titanium substrates (Fe-PbO{sub 2}/Ti). Chapter 4 discusses anodic evolution of ozone at Fe-PbO{sub 2}/Ti electrodes. Chap… more
Date: October 1, 1994
Creator: Feng, Jianren
Partner: UNT Libraries Government Documents Department
open access

Electrochemical abatement of pollutants NO{sub x} and SO{sub x} in combustion exhaust gases employing a solid-oxide electrolyte. Fourth quarterly report, July 1989--September 1989

Description: During the fourth quarter of this grant, the major accomplishment concerns the spectroscopic investigation of oxygen vacancies in YSZ and ESB. The nature of electrolytic ``blackening`` was studied. It was found that the same reduction processes that turn polycrystalline YSZ black turn single crystals orange. Two absorption bands attributable to this orange coloration, 328 and 470 nm, were observed. The 328 nm absorption band agrees with theoretical calculations for an F-center YSZ. Several fluo… more
Date: December 31, 1989
Creator: Stevenson, D. A. & Frank, C. W.
Partner: UNT Libraries Government Documents Department
open access

Synthesis and Characterization of CO- and H2S- Tolerant Electrocatalysts for PEM Fuel Cell: Final Report

Description: The present state-of-art Proton Exchange Membrane Fuel Cell (PEMFC) technology is based on platinum (Pt) as a catalyst for both the fuel (anode) and air (cathode) electrodes. This catalyst is highly active but susceptible to poisoning by CO, which may be present in the H{sub 2}-fuel used or may be introduced during the fuel processing. Presence of trace amount of CO in the H{sub 2}-fuel poisons the anode irreversibly and decreases the performance of the PEMFCs. In an effort to reduce the Pt-loa… more
Date: April 6, 2007
Creator: Ilias, Shamsuddin
Partner: UNT Libraries Government Documents Department
open access

Activity Report: A Report of Research Activity in Fiscal Years 1986 and 1987

Description: This report summarizes the last elements of work conducted in this program prior to its termination at the end of FY `87. The work was primarily an analysis of a fuel cell electrocatalyst using electron microscopy. The catalyst was a three component system containing Pt-Co-Ni (3:2:2 atomic ratios) dispersed on an amorphous carbon support in unknown phases, supplied to us by Giner Inc. (designated as their sample no. G82-5-19). The preparation of this catalyst is proprietary, (patent pending). O… more
Date: January 1988
Creator: Ross, P. N.; Beard, B. & Sattler, M.
Partner: UNT Libraries Government Documents Department
open access

Precious Metal Recovery from Fuel Cell MEA's

Description: In 2003, Engelhard Corporation received a DOE award to develop a cost-effective, environmentally friendly approach to recover Pt from fuel cell membrane electrode assemblies (MEA’s). The most important precious metal used in fuel cells is platinum, but ruthenium is also added to the anode electrocatalyst if CO is present in the hydrogen stream. As part of the project, a large number of measurements of Pt and Ru need to be made. A low-cost approach to measuring Pt is using the industry standard … more
Date: April 25, 2004
Creator: Shore, Lawrence
Partner: UNT Libraries Government Documents Department
open access

Carbon Nanotube Materials for Substrate Enhanced Control of Catalytic Activity

Description: Carbon SWNTs are attractive materials for supporting electrocatalysts. The properties of SWNTs are highly tunable and controlled by the nanotube's circumferential periodicity and their surface chemistry. These unique characteristics suggest that architectures constructed from these types of carbon support materials would exhibit interesting and useful properties. Here, we expect that the structure of the carbon nanotube support will play a major role in stabilizing metal electrocatalysts under … more
Date: May 1, 2007
Creator: Heben, M.; Dillon, A. C.; Engtrakul, C.; Lee, S. H.; Kelley, R. D. & Kini, A. M.
Partner: UNT Libraries Government Documents Department
open access

EFFECT OF PRETREATMENT ON PT-CO/C CATHODE CATALYSTS FOR THE OXYGEN-REDUCTION REACTION

Description: Carbon supported Pt and Pt-Co electrocatalysts for the oxygen reduction reaction in low temperature fuel cells were prepared by the reduction of the metal salts with sodium borohydride and sodium formate. The effect of surface treatment with nitric acid on the carbon surface and Co on the surface of carbon prior to the deposition of Pt was studied. The catalysts where Pt was deposited on treated carbon the ORR reaction preceded more through the two electron pathway and favored peroxide producti… more
Date: January 19, 2010
Creator: Fox, E. & Colon-Mercado, H.
Partner: UNT Libraries Government Documents Department
open access

Development of Novel Electrocatalysts for Proton Exchange Membrane Fuel Cells Annual Report

Description: The Proton Exchange Membrane Fuel Cell (PEMFC) is one of the most promising power sources for stand-alone utility and electric vehicle applications. Platinum (Pt) Catalyst is used for both fuel and air electrodes in PEMFCs. However, carbon monoxide (CO) contamination of H{sub 2} greatly affects electro catalysts used at the anode of PEMFCs and decreases cell performance. The irreversible poisoning of the anode can occur even in CO concentrations as low as few parts per million (ppm). In this wo… more
Date: June 11, 2002
Creator: Ilias, Shamsuddin
Partner: UNT Libraries Government Documents Department
open access

SYNTHESIS AND CHARACTERIZATION OF CO-AND H{sub 2}S-TOLERANT ELECTROCATALYSTS FOR PEM FUEL CELL

Description: The present state-of-art Proton Exchange Membrane Fuel Cell (PEMFC) technology is based on platinum (Pt) as a catalyst for both the fuel (anode) and air (cathode) electrodes. This catalyst is highly active but susceptible to poisoning by CO, which may be present in the H{sub 2}-fuel used or may be introduced during the fuel processing. Presence of trace amount of CO and H{sub 2}S in the H{sub 2}-fuel poisons the anode irreversibly and decreases the performance of the PEMFCs. In an effort to red… more
Date: March 30, 2003
Creator: Ilias, Shamsuddin
Partner: UNT Libraries Government Documents Department
open access

Synthesis and Characterization of CO- and H2S-Tolerant Electrocatalysts for PEM Fuel Cell Semi-Annual Technical Report: October 2004 - March 2005

Description: The present state-of-art Proton Exchange Membrane Fuel Cell (PEMFC) technology is based on platinum (Pt) as a catalyst for both the fuel (anode) and air (cathode) electrodes. This catalyst is highly active but susceptible to poisoning by CO, which may be present in the H{sub 2}-fuel used or may be introduced during the fuel processing. Presence of trace amount of CO and H{sub 2}S in the H{sub 2}-fuel poisons the anode irreversibly and decreases the performance of the PEMFCs. In an effort to red… more
Date: July 20, 2005
Creator: Ilias, Shamsuddin
Partner: UNT Libraries Government Documents Department
open access

DOE Laboratory Catalysis Research Symposium - Abstracts

Description: The conference consisted of two sessions with the following subtopics: (1) Heterogeneous Session: Novel Catalytic Materials; Photocatalysis; Novel Processing Conditions; Metals and Sulfides; Nuclear Magnetic Resonance; Metal Oxides and Partial Oxidation; Electrocatalysis; and Automotive Catalysis. (2) Homogeneous Catalysis: H-Transfer and Alkane Functionalization; Biocatalysis; Oxidation and Photocatalysis; and Novel Medical, Methods, and Catalyzed Reactions.
Date: February 1, 1999
Creator: Dunham, T.
Partner: UNT Libraries Government Documents Department
open access

Vectorial electron transfer in spatially ordered arrays. Progress report, January 1991--December 1991

Description: Progress has been made in four areas: the synthesis of new materials for directional electron; the preparation and characterization of anisotropic composites bearing organic and inorganic components; the elaboration of mechanisms of electrocatalysis; and the development of new methods for surface modification of metals and semiconductors.
Date: January 1, 1992
Creator: Fox, M. A.
Partner: UNT Libraries Government Documents Department
open access

IGR NO{sub x}/SO{sub x} control technology. Quarterly report October 1, 1994--December 31, 1994

Description: Work this quarter continued on the development of electrocatalysts and electrolyte materials and processing to improve the electrical efficiency required for economical NOx/SOx destruction. Efforts focused on two critical areas: first, modifying electrocatalyst composition in order to improve current efficiency, and, second, changing the solid state defect concentration in the solid oxide electrolyte itself.
Date: December 31, 1994
Partner: UNT Libraries Government Documents Department
open access

Development of Novel Electrocatalysts for Proton Exchange Membrane Fuel Cells Annual Report

Description: Proton Exchange Membrane Fuel Cell (PEMFC) is one of the most promising power sources for space and electric vehicle applications. Platinum (Pt) catalyst is used for both fuel and air electrodes in PEMFCs. The carbon monoxide (CO) contamination of H{sub 2} greatly affects electrocatalysts used at the anode of PEMFCs and decrease the cell performance. This irreversible poisoning of the anode can happen even in CO concentrations as low as few ppm, and therefore, require expensive scrubbing of the… more
Date: July 6, 2001
Creator: Ilias, Shamsuddin
Partner: UNT Libraries Government Documents Department
open access

Synthesis and Characterization of CO- and H2S-Tolerant Electrocatalysts for PEM Fuel Cell Semi-Annual Technical Report: April-September 2005

Description: The present state-of-art Proton Exchange Membrane Fuel Cell (PEMFC) technology is based on platinum (Pt) as a catalyst for both the fuel (anode) and air (cathode) electrodes. This catalyst is highly active but susceptible to poisoning by CO, which may be present in the H{sub 2}-fuel used or may be introduced during the fuel processing. Presence of trace amount of CO and H{sub 2}S in the H{sub 2}-fuel poisons the anode irreversibly and decreases the performance of the PEMFCs. In an effort to red… more
Date: December 22, 2005
Creator: Ilias, Shamsuddin
Partner: UNT Libraries Government Documents Department
open access

The application of solid-state NMR spectroscopy to electrochemical systems: CO adsorption on Pt electrocatalysts at the aqueous-electrode interface

Description: A fuel cell is an electrochemical energy conversion device, the continuous-flow analogue of the popular electrochemical storage device known as the battery. While the potential of fuel cells as power sources was recognized well over a century ago, they have since found limited application; a myriad of chemical, engineering and materials issues can be cited for this disappointing showing. Recent growing concern over the fate of the environment, however, has helped to renew interest in fuel cell … more
Date: December 1, 1996
Creator: Yahnke, M. S.; Reimer, J. A. & Cairns, E. J.
Partner: UNT Libraries Government Documents Department
open access

DEVELOPMENT OF NOVEL ELECTROCATALYST FOR PROTON EXCHANGE MEMBRANE FUEL CELLS

Description: Proton-exchange membrane fuel cell (PEMFC) is one of the strongest contenders as a power source for space & electric vehicle applications. Platinum catalyst is used for both fuel and air electrodes in PEMFCs. CO contamination of H{sub 2} greatly affects electrocatalysts used at the anode of polymer electrolyte fuel cells and decrease the cell performance. Pt-Ru catalyst had been recognized to alleviate this problem by showing better tolerance to CO poisoning than only Pt catalyst. This irrevers… more
Date: January 19, 2000
Creator: Ilias, Shamsuddin
Partner: UNT Libraries Government Documents Department
Back to Top of Screen