First-principles based modeling of hydrogen permeation through Pd-Cu alloys
Abstract
The solubility and diffusivity of hydrogen in disordered Pd1-xCux alloys are investigated using a combination of first-principles calculations, a composition-dependent local cluster expansion (CDLCE) technique, and kinetic Monte Carlo simulations. We demonstrate that a linear CDCLE model can already accurately describe interstitial H in Pd1-xCux alloys over the entire composition range (0\leqx\leq1) with accuracy comparable to that of direct first-principles calculations. Our predicted H solubility and permeability results are in reasonable agreement with experimental measurements. The proposed model is quite general and can be employed to rapidly and accurately screen a large number of alloy compositions for potential membrane applications. Extension to ternary or higher-order alloy systems should be straightforward. Our study also highlights the significant effect of local lattice relaxations on H energetics in size-mismatched disordered alloys, which has been largely overlooked in the literature.
Keywords
Cite
@article{arxiv.1204.4512,
title = {First-principles based modeling of hydrogen permeation through Pd-Cu alloys},
author = {Lin Qin and Chao Jiang},
journal= {arXiv preprint arXiv:1204.4512},
year = {2012}
}