Nanostructured C6B: A Novel Boron Rich Carbon for H2 Storage

EPA Grant Number: R830420C010
Subproject: this is subproject number 010 , established and managed by the Center Director under grant R830420
(EPA does not fund or establish subprojects; EPA awards and manages the overall grant for this center).

Center: Center for Environmental and Energy Research (CEER)
Center Director: Earl, David A.
Title: Nanostructured C6B: A Novel Boron Rich Carbon for H2 Storage
Investigators: Jones, Linda E. , Cormack, Alastair , Shelby, James
Institution: Alfred University
EPA Project Officer: Lasat, Mitch
Project Period: July 1, 2004 through December 31, 2005
RFA: Targeted Research Center (2004) Recipients Lists
Research Category: Hazardous Waste/Remediation , Targeted Research

Objective:

We proposed that a novel carbon, C6B, having a significantly large boron concentration (17 wt %) in the lattice, can be synthesized into novel carbon microstructures (keying on nanotubes). The unique nanostructure is one that is crenellated or puckered along the tube axis as a result of the presence of these large boron concentrations. Substitutional boron strains the lattice creating saddle points. The development of these saddle points, or folds, increases the total surface area of the nanostructured carbon. It was proposed that these fine structures can be incorporated with a regular and repeated periodicity, thereby enhancing active carbon area (area on which H2 is adsorbed). The net result is a nanotube or carbon nanostructure that has folds along the axis ultimately resulting in a significant enhancement of the surface area. In addition, this solid would be lighter than carbon and at a substitution of 17 wt %, a 2 percent increase in the specific energy of this H2 storage medium would be gained.

Furthermore, boron is expected to increase the adsorptive capacity of carbon on the basis of modifying carbon’s electronic structure. It is well established that boron modifies the electronic structure of both sp2 carbons (graphites) and boron-doped multiwalled nanotubes via the creation of defect sites in these solids. Boron thereby enables electron transfer, moving electrons away from regions of high electron density and distributing the electron population throughout the solid. In addition, boron is less electronegative than carbon, further contributing to a modification of the electron association with localized carbon sites. We do not now know how these two often-competing phenomena influence the adsorptive capacity of carbon, yet arguments can be made that increasing the defect site concentrations in these carbon solids will increase the numbers of active sites involved for adsorption and hence the total H2 adsorbed per weight of storage material.

Fundamental work is needed to understand the role of large concentrations of boron on the structure of carbons and carbon nanotubes and on electronic structure and therefore the adsorption of hydrogen. This study was undertaken to synthesize these novel carbons and evaluate their structures. We also proposed that, on the basis of this understanding, the synthesis of these novel carbons can be scaled to allow for a commercially viable and responsive H2 storage material.

The objective of this research project was to synthesize boron-rich nanotubes of composition C6B via chemical vapor deposition for the purpose of creating an H2 storage medium. We were building upon our experience with this novel form of carbon. The advantage of the C6B deposition process is that it enables high concentrations of boron to be placed in the solid throughout its growth process. Saddling, therefore, occurs in a continuous and periodic fashion. This material, when synthesized in a nanostructured form either as a nanotube or lower aspect-ratio possibly discontinuous form, would have extremely high active surface area for the adsorption of H2 as a result of the saddling created via the incorporation of 17 at.% boron into a hexagonal lattice.

Regarding carbon and phenomena of adsorption on carbons, we studied: (1) the role of boron on defect structure and concentrations; and (2) the nature of H2 adsorption on these defect sites.

Supplemental Keywords:

nanostructure, boron-doped carbon, hydrogen storage, carbon microstructures, nanotubes, CxB, nanotechnology, clean technologies, hydrogen economy, fuel cell technology, energy efficiency, alternative energy source,, RFA, Scientific Discipline, INTERNATIONAL COOPERATION, TREATMENT/CONTROL, Ecosystem Protection/Environmental Exposure & Risk, Sustainable Industry/Business, POLLUTION PREVENTION, Aquatic Ecosystems & Estuarine Research, Sustainable Environment, Energy, Technology, Aquatic Ecosystem, Technology for Sustainable Environment, Environmental Engineering, energy conservation, clean energy, cleaner production, sustainable development, clean technologies, nanotechnology, environmental conscious construction, green building design, clean manufacturing, energy efficiency, energy technology, nanomaterials, alternative energy source, water quality, environmentally conscious design, renewable energy

Progress and Final Reports:

  • 2005
  • Final Report

  • Main Center Abstract and Reports:

    R830420    Center for Environmental and Energy Research (CEER)

    Subprojects under this Center: (EPA does not fund or establish subprojects; EPA awards and manages the overall grant for this center).
    R828737C001 Environmental Impact of Fuel Cell Power Generation Systems
    R828737C002 Regional Economic and Material Flows
    R828737C003 Visualizing Growth and Sustainability of Water Resources
    R828737C004 Vibratory Residual Stress Relief and Modifications in Metals to Conserve Resources and Prevent Pollution
    R828737C005 Detecting and Quantifying the Evolution of Hazardous Air Pollutants Produced During High Temperature Manufacturing: A Focus on Batching of Nitrate Containing Glasses
    R828737C006 Sulfate and Nitrate Dynamics in the Canacadea Watershed
    R828737C007 Variations in Subsurface Denitrifying and Sulfate-Reducing Microbial Populations as a Result of Acid Precipitation
    R828737C008 Recycling Glass-Reinforced Thermoset Polymer Composite Materials
    R828737C009 Correlating Clay Mineralogy with Performance: Reducing Manufacturing Waste Through Improved Understanding
    R830420C001 Accelerated Hydrogen Diffusion Through Glass Microspheres: An Enabling Technology for a Hydrogen Economy
    R830420C002 Utilization of Paper Mill Waste in Ceramic Products
    R830420C003 Development of Passive Humidity-Control Materials
    R830420C004 Microarray System for Contaminated Water Analysis
    R830420C005 Material and Environmental Sustainability in Ceramic Processing
    R830420C006 Interaction of Sealing Glasses with Metallic Interconnects in Solid Oxide and Polymer Fuel Cells
    R830420C007 Preparation of Ceramic Glaze Waste for Recycling using Froth Flotation
    R830420C008 Elimination of Lead from Ceramic Glazes by Refractive Index Tailoring
    R830420C010 Nanostructured C6B: A Novel Boron Rich Carbon for H2 Storage