Alcoholysis features of lithium aluminum hydrides for its hydrolysis reaction at low-temperature

Abstract

Lithium aluminum hydrides are promising hydrogen storage materials due to their high hydrogen storage density. Hydrolysis of LiAlH4 is an ideal path to reach the operating temperature (−40/60 °C) target released by department of energy without extra heating processes. Ethylene glycol is a common antifreeze agent ingredient for low temperature reactions. However, the reaction features of ethylene glycol with LiAlH4 are still unknown. Here, the reaction behaviors of ethylene glycol with LiAlH4 have been studied. The reaction of LiAlH4 powder with ethylene glycol has been found to be hindered by the thin layer alcoholysis products on the surface. The alcoholysis products have been found to be easily react with water to yield Li–Al layered double hydroxides. The alcoholysis products have been demonstrated to be Li–Al double layered alcoholates, which is analogous to Li–Al layered double hydroxides. The ethylene glycol groups in the alcoholysis products are easily substituted by –OH in the presence of water. Thus, only water is consumed from the antifreeze agents for low temperature hydrogen release.