Abstract

MgH2 based composites combined with NaNH2 were synthesized by mechanical milling for three different milling times ranging from 15 to 60 minutes. Microstructure and particle size of the samples were analyzed by SEM microscopy while desorption properties were followed by Thermal Desorption Spectroscopy (TDS). The kinetic properties of NaNH2-MgH2 composites were investigated by isoconversional kinetic method as implemented in code developed by our group. Composites show hydrogen desorption peaks shifted to lower temperatures in comparison to mechanically modified and as received MgH2. All NaNH2-MgH2 composites show enhanced kinetics with lowered apparent activation energy (Ea) in comparison to milled MgH2. The mechanism of desorption changes from Avrami–Erofeev n = 3 for as received MgH2 to Avrami–Erofeev n = 4 for composite materials. The change from 3 to 4 can be due to the modification of the nucleation process or a change in the dimensionality of the growth. Those high values of n disregard a diffusion control as a rate limiting step. It has been shown that there is a synergistic effect on the enhanced hydrogen storage performance of chemical reaction and structural changes caused by ball milling. This can be used as a starting point for synthesis of innovative hydrogen storage materials.

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.