Micro-channel development and hydrogen adsorption properties in templated microporous carbons containing platinum nanoparticles
|dc.identifier.citation||Yang, Y. and Brown, C. and Zhao, C. and Chaffee, A. and Nick, B. and Zhao, D. and Webley, P. et al. 2011. Micro-channel development and hydrogen adsorption properties in templated microporous carbons containing platinum nanoparticles. Carbon. 49 (4): pp. 1305-1317.|
Ordered microporous carbons containing dispersed platinum nanoparticles were fabricated and chosen as suitable models to investigate micro-structure development and hydrogen transport properties of zeolite-templated carbons. X-ray photoelectron spectroscopy analysis revealed that the enhanced heat of adsorption is related to the narrow micro-channels templated from the zeolite and the presence of certain Csingle bondO groups on the carbon. The lack of a well-defined and intense rotational transition line and the persistent broad H2 recoil spectrum in neutron scattering results suggests a distribution of binding sites. Most interestingly, hydrogen diffusion occurs on two time scales, consisting of a fast liquid-like jump diffusion on the timescale of picoseconds along with an even faster bulk-like diffusion. The liquid-like motion is characterized by a diffusion constant of (2.1 ± 0.3) × 10−8 m2/s with an activation energy of ca. 77 K; both values indicate somewhat lower mobility than similar dynamics of H2 on nanotubes, activated carbon XC-72, or Grafoil, yet greater mobility than that of bulk liquid. These unusual characteristics for hydrogen in carbons are believed to arise from the network of narrow pores in this zeolite-templated image of the zeolite. In fact, the diffusion constants of the templated carbons are extremely similar to those measured for zeolite 13X.
|dc.title||Micro-channel development and hydrogen adsorption properties in templated microporous carbons containing platinum nanoparticles|
|curtin.department||Department of Physics and Astronomy|
|curtin.accessStatus||Fulltext not available|
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