Theoretical investigation of molecular hydrogen adsorption and dissociation on AlnV(n=1-13) clusters

We present density functional calculations of H-2 adsorption and dissociation on small-sized AlnV clusters for n = 1-13. The growth pattern for AlnV (n = 2-4, 8, 10-12) clusters is V atom occupying a peripheral position of Al-n, clusters. And the growth pattern for AlnV (n = 6, 9, and 13) clusters is V-substituted Aln+1 clusters. It is found that the V atom substituted the surface atom of Aln+1 cluster and occupies a peripheral position. H-2 is easily physically absorbed on the top V atom of AlnV (n = 1-13) clusters with a side-on orientation rather than an end-on orientation because of the more effective orbital overlap in the side-on orientation. The reaction of AlnV with H-2 would produce AlnVH2 because of large exothermic energy changes and relatively small activation energies especially for AlV and Al7V, which might serve as highly efficient and low-cost catalysts for hydrogen dissociation. Copyright (C) 2013, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.