Investigation of hydrogen storage on Sc/Ti-decorated novel B24N24

Inspired by the TM-N-4 coordination environment in single-atom catalysts, four novel TM decorated B24N24 (TM = Sc, Ti) fullerenes with six TM-N-4 or TM-B-4 units are designed. Molecular dynamic simulations confirm that the four TM6B24N24 fullerenes are thermodynamically stable. Their hydrogen storage properties were investigated using density functional theory calculations. Sc/Ti atoms bind to the N-4/B-4 cavities with an average interaction energy of 6.30-11.96 eV. Hence, the problem of clustering can be avoided. 36H(2) could be adsorbed with average hydrogen adsorption energies of 0.18-0.55 eV. The lowest hydrogen desorption temperatures at atmospheric pressure for Sc6B24N24(N-4)-36H(2), Sc6B24N24(B-4)-36H(2), Ti6B24N24(N-4)-36H(2), and Ti6B24N24(B4)-36H(2) are 255 K, 318 K, 243 K, and 408 K, respectively. The maximum hydrogen gravimetric densities of the Sc6B24N24 and Ti6B24N24 systems are 7.74 wt% and 7.50 wt%, respectively. Therefore, the novel Sc6B24N24 and Ti6B24N24 could be suitable as potential hydrogen storage materials at ambient temperature. (C) 2020 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.