LiBH4 Electronic Destabilization with Nickel(II) Phthalocyanine—Leading to a Reversible Hydrogen Storage System

Abstract

Precipitation of a LiBH4 solution into an antisolvent led to formation of nanoparticles in the size range of 2 to 18 nm. By direct deposition of these nanoparticles onto a nickel(II) phthalocyanine substrate, LiBH4 was destabilized and the hydrogen release temperature was dramatically reduced to 350 °C through a single step decomposition. Remarkably, upon hydrogen release and uptakes, the morphology of the material evolved to single crystal “plates”-like particles and a reversible hydrogen storage capacity of 3.2 mass% at 350 °C under 6 MPa H2 pressure was observed. As evident by X-ray photoelectron spectroscopy analysis, such an enhancement is believed to result from the effective electron transfer interplay between LiBH4, LiH, B, and the nickel(II) phthalocyanine, enabling a destabilization of LiBH4 and the facile rehydrogenation of LiH and B into LiBH4. This study thus reveals a novel approach to destabilize LiBH4 by the use of an “electron active” substrate.