Ultrasmall MgH_2 Nanoparticles Embedded in an Ordered Microporous Carbon Exhibiting Rapid Hydrogen Sorption Kinetics
Abstract
MgH_2 nanoparticles with different average sizes have been prepared as ordered microporous carbon by tuning the Mg amount from 15 to 50 wt %. Ultrasmall particles with mean sizes of 1.3 and 3.0 nm have been obtained for 15 and 25 wt % Mg contents, respectively. The hydrogen desorption properties strongly depend on the nanoparticle size, as evidenced by different thermal analysis techniques. The onset temperature of hydrogen desorption for MgH_2 nanoparticles below 3 nm occurs at a temperature about 245 K lower than for microcrystalline material. Two distinct hydrogen desorption peaks are noticed for nanoparticles with mean sizes of 1.3 and 3.0 nm, as confirmed by TDS and HP-DSC. 1H NMR investigations suggest the presence of two MgH_2 populations with enhanced hydrogen mobility, as compared to the microcrystalline hydride. The short hydrogen diffusion path and the enhanced hydrogen mobility may explain the increased desorption kinetics of these ultrasmall nanoparticles.
Additional Information
© 2015 American Chemical Society. Received: June 16, 2015; revised: July 10, 2015; published: July 21, 2015. This work was financially supported by the Université Paris-Est Créteil. We acknowledge Julie Bourgon and Eric Leroy for performing TEM measurements and Khaled Bouhlel for valuable help with sample preparation. We thank Peter Bramwell for TPD measurements at Utrecht University. The IEA HIA network is acknowledged for providing opportunities for collaborations and fruitful discussions.Attached Files
Supplemental Material - jp5b05754_si_001.pdf
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Additional details
- Eprint ID
- 60073
- Resolver ID
- CaltechAUTHORS:20150904-105218571
- Université Paris-Est Créteil
- Created
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2015-09-09Created from EPrint's datestamp field
- Updated
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2021-11-10Created from EPrint's last_modified field