A DFT Study of Hydrogen Storage in High-Entropy Alloy TiZrHfScMo

Area of Science:

• Materials Science
• Physical Chemistry
• Computational Materials Science

Background:

• High-entropy alloys (HEAs) are emerging as candidates for hydrogen storage applications.
• A theoretical understanding of hydrogen absorption in HEAs is currently lacking.
• Investigating novel HEAs is crucial for advancing hydrogen storage technologies.

Purpose of the Study:

• To investigate the hydrogen storage properties of a newly synthesized TiZrHfScMo high-entropy alloy.
• To provide a theoretical basis for understanding hydrogen absorption mechanisms in this HEA.
• To evaluate the potential of TiZrHfScMo as a hydrogen storage material.

Main Methods:

• Successful synthesis and characterization of the TiZrHfScMo alloy with a body-centered cubic structure.
• Application of density functional theory (DFT) for calculating key properties.
• Analysis of lattice constant, formation enthalpy, binding energy, and electronic properties of hydrogenated TiZrHfScMo.

Main Results:

• Hydrogenation of TiZrHfScMo is an exothermic process.
• Covalent bonding characterizes the interaction between hydrogen and metal elements.
• Ti and Sc atoms lose electrons, while Mo atoms gain electrons upon hydrogenation.
• Ti-H bonding weakens, and Hf-H and Mo-H bonding strengthens with increasing hydrogen content.

Conclusions:

• The TiZrHfScMo high-entropy alloy demonstrates significant promise for hydrogen storage.
• Different constituent elements play distinct roles in the hydrogen absorption process.
• DFT calculations provide valuable insights into the hydrogen storage mechanisms of HEAs.