Masika, E, Bourne, RA, Chamberlain, TW et al. (1 more author) (2013) Supercritical CO2 mediated incorporation of Pd onto templated carbons: a route to optimizing the Pd particle size and hydrogen uptake density. ACS Applied Materials and Interfaces, 5 (12). 5639 - 5647. ISSN 1944-8244
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.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Keywords: | hydrogen storage; palladium nanoparticles; pore size distribution; supercritical CO2; zeolite-templated carbon |
Dates: |
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Institution: | The University of Leeds |
Academic Units: | The University of Leeds > Faculty of Engineering & Physical Sciences (Leeds) > School of Chemical & Process Engineering (Leeds) > Institute for Particle Science and Engineering (Leeds) |
Depositing User: | Symplectic Publications |
Date Deposited: | 03 Apr 2014 10:21 |
Last Modified: | 11 Apr 2014 10:38 |
Published Version: | http://dx.doi.org/10.1021/am401622w |
Status: | Published |
Publisher: | American Chemical Society |
Identification Number: | 10.1021/am401622w |
Related URLs: | |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:78346 |