Isomeric Thiadiazole-xLi+(x = 1, 2) templates found to be efficient in search of potential H2 storage systems; a computational study

Abstract

The hydrogen trapping possibility of isomeric thiadiazole-Li+ and thiadiazole-2Li+ building blocks has been evaluated by various functionals within density functional theory (DFT), and it is found that they can adsorb a maximum of five and ten H2 molecules respectively. Aromaticity is retained even after hydrogen adsorption. Average adsorption energy lies in the quasimolecular type adsorption range. The gravimetric wt% (9.7 ∼ 16.7) are found suitable as per norms. Topological analysis shows that the bond formation between Li and trapped H2 molecules is mostly non-covalent. At 200 K or below this temperature, the Gibbs free energy changes illustrate that the molecular hydrogen adsorption process is spontaneous for all isomeric thiadiazole-xLi+ [x = 1 and 2] building blocks. Higher temperatures are required for the desorption of H2 molecules. Thus, we believe that our studied system thiadiazole-xLi+ can be proposed as a practically viable system for hydrogen storage.