Additive Effects of LiBH₄ and ZrCoH₃ on the Hydrogen Sorption of the Li-Mg-N‑H Hydrogen Storage System

Abstract

LiBH₄ is an effective catalyst for the hydrogen sorption of the Li-Mg-N-H storage system. A combination of LiBH₄ with ZrCoH₃ was reported to be catalytically more effective. In this work, materials doped with LiBH₄ or ZrCoH₃ or a combination of ZrCoH₃ and LiBH₄ were characterized both in the as-prepared and in the cycled states. A comparison of the metathesis conversion, thermal behavior, kinetics, and phase evolution induced by H₂ cycling suggests that the two components function additively. While LiBH₄ facilitates the metathesis conversion in the first cycle and enhances kinetics during H₂ cycling by forming a quaternary complex hydride, ZrCoH₃ has at least a pulverizing effect in the material. The chemical environment and near order of the individual atoms of Zr and Co as well as the structural parameters of ZrCoH₃ were investigated by X-ray absorption and found to be unchanged during H₂ cycling