Hydrogen adsorption on lithium-functionalized calixarenes: A computational study

In this work, density functional theory (DFT) was performed to investigate hydrogen storage in Li-functionalized p-tert-butyl calixarene (LTBC). Calculations based on DFT show that Li-functionalized calixarene significantly improves the average binding energy of hydrogen molecules. Each Li-functionalized calixarene molecules was found to hold four hydrogen molecules inside its cavity, yielding an approximate gravimetric density of ̃ 10 wt %. Furthermore, the ab initio molecular dynamics simulations show that LTBC molecules are stable up to 200 K. Finally, the pair distribution function calculated for LTBC with four hydrogen molecules inside the cavity shows that the hydrogen molecules are stable inside the cavity until 100 K.