Exploring the structure and hydrogen storage capacity of CeH^0/+ clusters

Area of Science:

• Materials Science
• Computational Chemistry
• Hydrogen Storage

Background:

• Rare earth elements, with their unique 4f orbitals, are crucial for enhancing hydrogen storage materials.
• Cerium hydride (CeH_n) clusters are being investigated for their potential in advanced hydrogen storage applications.

Purpose of the Study:

• To determine the stable structures of neutral and cationic cerium hydride (CeH_n^0/+, n=2-20) clusters.
• To evaluate the hydrogen storage capacity and stability of these clusters.

Main Methods:

• Utilized the Crystal Structure AnaLYsis by Particle Swarm Optimization (CALYPSO) method.
• Employed density functional theory (DFT) for structural and electronic analysis.
• Calculated adsorption energies and analyzed molecular orbital composition.

Main Results:

• Identified stable structures for CeH₁₃ (doublet, C_s symmetry) and CeH₁₄⁺ (doublet, C_2v symmetry).
• Observed preferential chemical adsorption of hydrogen atoms onto cerium atoms.
• Attributed cluster stability to hybridization between H 1s and Ce 4f orbitals.

Conclusions:

• CeH₁₃ and CeH₁₄⁺ clusters demonstrate remarkable stability and significant hydrogen storage capacities of 8.5 wt% and 9.1 wt%, respectively.
• These findings highlight the potential of cerium hydride clusters for efficient hydrogen storage solutions.