文摘
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.