Low-temperature chemical synthesis of intermetallic TiFe nanoparticles for hydrogen absorption

Nanosizing of TiFe hydrogen storage alloy is conducted to facilitate its activation. Here, pure intermetallic TiFe nanoparticles (45 nm) were prepared using chemical reduction of oxide precursors at 600 degrees C, which is the lowest temperature ever used in chemical synthesis. This was achieved using a strong reducing agent (CaH2) in a molten LiCl. When used for hydrogen absorption, the obtained nanoparticles surprisingly exhibited almost no hydrogen absorption. The results demonstrated that TiFe nanoparticles are more difficult to activate than the bulk powder because the oxidized surface layers of the nanoparticles become stabilized, which prevents the morphological change necessary for their activation. (C) 2021 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.

Automated summary

The nano-sized TiFe hydrogen storage alloy was found to be more difficult to activate than the bulk powder, due to the stabilized oxidized surface layers of the nanoparticles preventing the morphological change necessary for activation.