Hydrogen adsorption in mesoporous carbons
ABSTRACT The hydrogen adsorption of mesoporous carbon materials with different mesostructures, surface areas, and pore volumes has been investigated. Experimental results indicate that the hydrogen adsorption capacities are dominantly related to their surface areas. A hydrogen adsorption capacity of 1.78 wt % was obtained at 77 K and ambient pressure of 850 mm Hg (0.11 MPa) for the mesoporous carbon with a surface area of 2314 m 2/ g .
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ABSTRACT: Zeolite templating successfully generates carbons with high surface area and pore volume of ca. 3300 m2 g−1 and 1.6 cm3 g−1, respectively. The templated carbons have an exceptional gravimetric hydrogen uptake of 7.3 wt% at 20 bar and −196 °C, and a projected maximum of ca. 9.2 wt%. These hydrogen uptake values are the highest ever recorded for carbon materials. The zeolite templated carbons have excellent mechanical stability and when compacted at a load of 10 tons (740 MPa) undergo densification to a packing density of ca. 0.72 g cm−3 but with hardly any loss in porosity (surface area and pore volume are little changed at ca. 3000 m2 g−1 and 1.4 cm3 g−1) or gravimetric hydrogen uptake capacity, which remains high at 7.0 wt% at 20 bar and a projected maximum of ca. 8.8 wt%. The effects of densification (i.e., increased packing density) coupled with hardly any loss in porosity or hydrogen uptake means that the densified zeolite templated carbons achieve an exceptional and unprecedented volumetric hydrogen uptake of 50 g l−1 at −196 °C and 20 bar, and an estimated maximum of up to 63 g l−1 at higher pressure.Energy & Environmental Science 01/2014; 7(1):427. DOI:10.1039/c3ee42239a · 15.49 Impact Factor
Conference Paper: Hydrogen Storage on Carbonized Chicken Feather Fibers[Show abstract] [Hide abstract]
ABSTRACT: Due to its environment-friendly features and high energy potential, hydrogen can be an ideal energy carrier for the future. However, there still are serious problems in the production and storage of hydrogen. The Department of Energy's (DOE) 2010 and 2015 hydrogen storage targets are quite challenging in terms of gravimetric capacity (6 wt% and 9 wt% respectively), volumetric capacity (45 and 81 grams H2 per L), storage cost ($4 and $2 per kWh respectively) and practical usage i.e., safety, short refueling time and long cycle life. Chicken feather fibers (CFF), which are an agricultural waste, have great potential to become main hydrogen storage material because of their hollow structure and low cost. When 92% keratin chicken feathers are carbonized by controlled pyrolysis, it is observed that the hollow structure of the keratin fibers does not change. Their surface area increases by the formation of fractals and micropores and their mean pore diameter decreases down to 5 Ǻ thus enabling more hydrogen adsorption than raw (untreated) feather fibers. The main objectives of this study are investigating the details of the carbonization process of feather fibers, modifying and decorating their surface for higher hydrogen storage capacities. Hydrogen storage, pyrolysis, nitrogen adsorption, XPS and FTIR measurements will be presented. This project was supported by the National Research Initiative of the USDA Cooperative State Research, Education and Extension Service, grant number 2005-35504-16137.12th Annual Green Chemistry and Engineering Conference; 06/2008
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ABSTRACT: Spherical clusters of transition-metal oxide nanorods were prepared by using a simple, rapid and easily scaled up method, i.e. chemical precipitation followed by thermal decomposition. The microstructural characteristics of spherical clusters of nanorods were examined by scanning electron microscopy (SEM). It was found that the nanorods were displayed on the surfaces of the spherical particles that had grown from the center of the spherical particles to their surface. It is worth pointing out that the spherical clusters of nanocrystals could serve as effective confined templates for spherical nanostructures. Hydrogen adsorption/desorption experiments were carried out at room temperature. A hydrogen storage capacity of 0.71% was achieved under a pressure of 3.05 MPa for spherical clusters of doped NiO nanorods with a surface area of 113.39 m2/g, and about 66.8% of the stored hydrogen could be released under ambient pressure.Materials Letters 12/2006; 60(29-30):3891-3894. DOI:10.1016/j.matlet.2006.03.135 · 2.27 Impact Factor