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Supercritical CO2 Mediated Incorporation of Pd onto Templated Carbons: A Route to Optimizing the Pd Particle Size and Hydrogen Uptake Density

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dc.contributor.author Masika, E.
dc.contributor.author Mokaya, R.
dc.contributor.author Bourne, Richard A.
dc.contributor.author Chamberlain, Thomas W.
dc.date.accessioned 2014-10-14T13:21:09Z
dc.date.available 2014-10-14T13:21:09Z
dc.date.issued 2013-06
dc.identifier.citation ACS Applied Materials and Interfaces, vol. 5, pp.5639-5647. 2013. en_US
dc.identifier.issn 1944-8244
dc.identifier.issn 1944-8252
dc.identifier.uri http://dx.doi.org/10.1021/am401622w
dc.identifier.uri http://ir-library.ku.ac.ke/handle/123456789/11458
dc.description http://dx.doi.org/10.1021/am401622w en_US
dc.description.abstract Palladium nanoparticles are deposited onto zeolite template carbon (ZTC) via supercritical CO2 (scCO2) mediated hydrogenation of a CO2-phillic transition metal precursor. The supercritical fluid (SCF) mediated metal incorporation approach enabled the decoration of ZTC with 0.2-2.0 wt % of well-dispersed Pd nanoparticles of size 2-5 nm. The resulting Pd-doped ZTCs exhibit enhanced hydrogen uptake and storage density. The ZTC (with surface area of 2046 m(2)/g) had a hydrogen storage capacity (at 77 K and 20 bar) of 4.9 wt %, while the Pd-ZTCs had uptake of 4.7-5.3 wt % despite a surface area in the range 1390-1858 m(2)/g. The Pd-ZTCs thus exhibit enhanced hydrogen storage density (14.3-18.3 μmol H2/m(2)), which is much higher than that of Pd-free ZTC (12.0 μmol H2/m(2)). The hydrogen isosteric heat of adsorption (Qst) was found to be higher for the Pd-doped carbons (6.7 kJ/mol) compared to the parent ZTC (5.3 kJ/mol). The deposition of small amounts of Pd (up to 2 wt %) along with well-dispersed Pd nanoparticles of size of 2-5 nm is essential for the enhancement of hydrogen uptake and illustrates the importance of optimizing the balance between metal loading/particle size and surface area to achieve the best metal/porous carbon composite for enhanced hydrogen uptake en_US
dc.language.iso en en_US
dc.publisher American Chemical Society en_US
dc.title Supercritical CO2 Mediated Incorporation of Pd onto Templated Carbons: A Route to Optimizing the Pd Particle Size and Hydrogen Uptake Density en_US
dc.type Article en_US


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