Ab-Initio Determination of Palladium Hydride Properties and Application to Hydrogen Storage

Abstract

In this work, we presented a theoretical study on the structural and electronic properties of palladium  hydride and demonstrated the usefulness of modelling by choosing the most appropriate hydride to find the possibility of storing hydrogen as a new energy in the palladium. Thus, the structural and electronic properties of pure palladium were compared with those of palladium hydrides PdH_x (x = 0.25, 0.50, 0.75, 1) using the ab-initio method known as the linear augmented plane wave method (FP-LAPW) based on density functional theory calculations, implemented in the Wien2k code. The results obtained for band structure and state density have been improved to previous theoretical work and showed that hydrogen absorption is accompanied by a significant dilation of the crystalline lattice. The PdH_x hydride possesses metallic properties, and both total and partial DOS calculations show that the palladium 3d and hydrogen 1s states exhibit the greatest hybridization. In the palladium hydrides studied PdH_x, the electrons decrease their energy leading to a large binding force between Pd and H atoms which leads to a more stable system.