Hydrogen storage in Pd clusters

Abstract

Hydrogen storage in a Pd cluster is studied theoretically using a self-consistent densityfunctional scheme with a norm-conserving pseudopotential. We mainly focus on the cuboctahedral Pd 13 H n clusters with n = 1, 6, 8, and 14. Two stable sites for hydrogen adsorption are found; one is slightly inside the square face of the cluster and the other is outside of the triangular face. Electronic states relevant to hydrogen adsorption are well described by the cluster-centre electronic states (CCSs); this term refers to the states produced by the centre cluster (hydrogen atoms and the centre Pd atom) interacting with peripheral Pd atoms. When the hydrogen atoms are adsorbed inside the tetrahedral face, the cluster is stabilized by expanding the Pd-Pd distance by 3.7%, which is close to the lattice expansion in the β-phase of bulk PdH. As the face-centred-cubic bulk can be fully 'clusterized' by these clusters, we estimate the entropy change of the bulk upon transition as the change in configuration entropy between these clusters.

Chemisorption of hydrogen on Fe clusters through hybrid bonding mechanisms

“…[7][8][9][10] Fe-H interaction at nanoscale is not an exception. Whetten et al suggests that gas phase small Fe clusters could form chemical bonds with H. 11 FeH molecules were detected by the near-infrared spectrum and the blue-green solar spectrum.…”

“…Hydrogenated Fe 1 has symmetrical configuration as can be seen in Figure 1. Additionally, the structure of hydrogenated Fe 1 forms 2-dimensional configurations until Fe 1 H 6 , where a 3-dimensional configuration then starts to form from FeH 7 .…”

First-principles study of alloying effect of transition metals on He in titanium ditritide

“…It is found that the behavior and electronic structure of H in clusters are similar to those in a crystal [15][16][17][18]. Besides quite a few reports about alloying effects on different systems by using the cluster model [19][20][21][22][23][24][25], Yang et al [26] recently employed a cluster model to study the transition metal alloying effect on the chemical bonding in TiH 2 .…”

Fabrication and Characterization of Percolating Nanocluster Devices

“…Recently, research has been focused on palladium (Pd) nanoclusters because of possible applications in the fields of hydrogen storage [1,2], hydrogen detection [3], and catalysts [4,5]. Therefore, intensive research is required to develop nanocluster sources to produce more intensive nanocluster beam, and to provide further control of nanocluster size distributions [6,7].…”