Feasibility of Li decorated C8 carbyne ring as a promising hydrogen storage media. DFT study

This study takes a unique approach by simulating the hydrogen storage properties of a carbyne C8-ring molecule decorated with lithium atoms on its outer surface. The simulations used the Density Functional Theory (DFT) formalism with the GGA-PBE functional in the Biovia Materials Studio Dmol3 modeling and simulation program. The results revealed that a maximum of 4 H2 molecules were physisorbed per Li atom, with an average binding energy of 0.22 eV/H2. This physisorption led to a gravimetric capacity of 7.25 wt.% and a volumetric capacity of 0.046 kg H2/L. The thermal stability and desorption temperature of LiC8-4H2 were determined by Molecular Dynamics calculations and the Van´t Hoff equation, showing that hydrogen molecules were easily desorbed at room temperature T= 300 K. These findings highlight the potential of Li-decorated carbyne as a promising material for hydrogen storage with applications in fuel cells.