H and Li dynamics in Li12C60 and Li(12)C(60)Hy

摘要

Lithium and hydrogen dynamics in Li12C60 and Li(12)C(60)Hy are investigated by means of Li-7 and H-1 solid state Nuclear Magnetic Resonance (NMR) in the temperature range 80-550 K. Differential scanning calorimetry characterization on the hydrogen sorption and X-rays structural analysis are also reported. In the pure phase, the Li-7 results show a thermally activated dynamics that can be associated to Li motions within the crystal interstices. Upon hydrogenation, Li ionic motion is considerably hindered by the presence of hydrofullerene molecules. The H-1 measurements show that C-H, bonds are stable on the local scale up to 400-450 K. The NMR results at higher temperatures are compatible with a H diffusion mechanism which anticipates the H desorption process. (C) 2017 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.