Electronic Structure Calculations of Reversible Hydrogen Storage in Nanoporous Ti Cluster Frameworks

Abstract

Hydrogen is the most potential substitute for fossil fuels in automobiles and shifting to a sustainable energy source. The lack of high-density hydrogen storage materials impedes the use of hydrogen as a fuel. In this study, a porous metal cluster framework (MCF) with Ti cluster as a linker has been reported for the first time. This framework has a pore size of 2.204 nm and a vertical length of 2.597 nm. Using density functional theory, the hydrogen storage capacity and the mechanism of adsorption have been investigated. The Kubas interaction is observed during the hydrogen adsorption process with adsorption energy in the range of 0.22− 0.25 eV, and the maximum hydrogen weight percentage is found to be 9.6%. Our findings from Born−Oppenheimer molecular dynamics, van ‘t Hoff desorption study, and occupation number reveal that MCF reversibly adsorbs hydrogen with high gravimetric density under ambient thermodynamic conditions. MCF fulfills the targets of the U.S. Department of Energy, which makes it a promising reversible hydrogen storage candidate.