Investigation of Phase Stability of Magnesium Alanate for Hydrogen Storage From First Principles

Developed by: AIChE
  • Type:
    Conference Presentation
  • Conference Type:
    AIChE Annual Meeting
  • Presentation Date:
    October 30, 2012
  • Duration:
    30 minutes
  • Skill Level:
    Intermediate
  • PDHs:
    0.50

Share This Post:

Complex hydrides including alanates ([AlH4]) have recently gained attention as alternative hydrogen storage materials. Many of these materials have been known to release hydrogen upon contact with water; however, the hydrolysis reactions are highly irreversible, a process known as “one-pass” hydrogen storage. Nanostructuring and nanocatalysis have been accepted as promising methods to overcome the irreversible hydrogenation process. Thus, predicting which phases may be more stable as a function of nanoparticle size may contribute to nanostructuring complex hydrides for hydrogen storage applications. We have employed density functional theory (DFT) using the projector-augmented wave (PAW) method within the generalized gradient approximation (GGA) to calculate relatively smaller nanoparticles of magnesium alanate (Mg(AlH4)2) ranging from 1 to 2 nm. Based upon these results, cluster expansion and Monte Carlo simulation methods were developed to predict the phase stabilities of 2-10 nm Mg(AlH4)2 nanoparticles. Our calculations provide phase stability diagrams of Mg(AlH4)2 nanoparticles as a function of particle size and temperature. This study may help identify how the relative stability of different compounds (Mg(AlH4)2, MgH2, Al, and H2) evolves as a function of nanoparticle size and temperature, which will facilitate experimental studies to determine the thermodynamically favored reaction pathways for the hydrogenation/dehydrogenation processes of Mg(AlH4)2.
Presenter(s): 
Once the content has been viewed and you have attested to it, you will be able to download and print a certificate for PDH credits. If you have already viewed this content, please click here to login.

Checkout

Checkout

Do you already own this?

Log In for instructions on accessing this content.

Pricing

AIChE Member Credits 0.5
AIChE Members $15.00
AIChE Undergraduate Student Members Free
AIChE Graduate Student Members Free
Non-Members $25.00