Hydrogen, while a promising sustainable energy carrier, presents challenges such as the embrittlement of materials due to its ability to penetrate and weaken their crystal structures. Here we investigate Fe4N nitride layers, formed on iron through a cost-effective gas nitriding process, as an effective hydrogen permeation barrier. A combination of screening using advanced characterization, density functional theory calculations, and hydrogen permeation analysis reveals that a nitride layer reduces hydrogen diffusion by a factor of 20 at room temperature. This reduction is achieved by creating energetically unfavorable states due to stronger H-binding at the surface and high energy barriers for diffusion. The findings demonstrate the potential of Fe4N as a cost-efficient and easy-to-process solution to protecting metallic materials exposed to hydrogen, with great advantages for large-scale applications.
@article{arxiv.2410.04059,
title = {An atomic-scale view at Fe4N as hydrogen barrier material},
author = {Aleksander Albrecht and Sang Yoon Song and Chang-Gi Lee and Mathias Krämer and Su-Hyun Yoo and Marcus Hans and Baptiste Gault and Yan Ma and Dierk Raabe and Seok-Su Sohn and Yonghyuk Lee and Se-Ho Kim},
journal= {arXiv preprint arXiv:2410.04059},
year = {2024}
}