Abstract

The present paper reports the effect of graphitic nanofibres (GNFs) for improving the desorption kinetics of LiMg(AlH 4) 3 and LiAlH 4. LiMg(AlH 4) 3 has been synthesized by mechano-chemical metathesis reaction involving LiAlH 4 and MgCl 2. The enhancement in dehydrogenation characteristics of LiMg(AlH 4) 3 has been shown to be higher when graphitic nanofibres (GNFs) were used as catalyst. Out of two different types of nanofibres namely planar graphitic nanofibre (PGNF) and helical graphitic nanofibre (HGNF), the latter has been found to act as better catalyst. We observed that helical morphology of fibres improves the desorption kinetics and decreases the desorption temperature of both LiMg(AlH 4) 3 and LiAlH 4. The desorption temperature for 8 mol% HGNF admixed LiAlH 4 gets lowered from 159 °C to 128 °C with significantly faster kinetics. In 8 mol% HGNF admixed LiMg(AlH 4) 3 sample, the desorption temperature gets lowered from 105 °C to ∼70 °C. The activation energy calculated for the first step decomposition of LiAlH 4 admixed with 8 mol% HGNF is ∼68 kJ/mol, where as that for pristine LiAlH 4 it is 107 kJ/mol. The activation energy calculated for as synthesized LiMg(AlH 4) 3 is ∼66 kJ/mol. Since the first step decomposition of LiMg(AlH 4) 3 occurs during GNF admixing, the activation energy for initial step decomposition of GNF admixed LiMg(AlH 4) 3 could not be estimated.

Full Text
Paper version not known

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.