First-principles study of hydrogen incorporation into the MAX phase Ti 3 AlC 2

Haimin Ding (1) , Nicolas Glandut (2) , Xiaoliang Fan (1) , Qing Liu (1) , Yu Shi (1) , Jinchuan Jie (3)

1 North China Electric Power University
2 SPCTS-AXE2 - Axe 2 : procédés plasmas et lasers
3 Dalian University of Technology

First-principles calculations have been performed to study hydrogen incorporation into the MAX phase Ti3AlC2. It is found that H atoms are thermally favorable to be incorporated into the interstitial sites of Ti-Al layers in stoichiometric Ti3AlC2. Only when C vacancies exist, H atoms can be incorporated into Ti-C layers. In Ti-Al layers, the hexagonal interstitial site (Ihexa) consisting of three Al atoms and two Ti atoms, the tetrahedral interstitial site (Itetr-2) consisting of one Al atom and three Ti atoms, and the octahedral interstitial site (Ioct-3) consisting of three Ti atoms and three Al atoms are all possible sites for H incorporation. Among them, Itetr-2 is the most stable one, followed by Ioct-3, and the last one is Ihexa sites. The linear synchronous transit optimization study shows that the diffusion of H in the Ti-Al layers is feasible which could be helpful for the continuous insertion and the following extraction of H in Ti3AlC2.

Domaines: Matériaux; Matériaux

Haimin Ding, Nicolas Glandut, Xiaoliang Fan, Qing Liu, Yu Shi, et al.. First-principles study of hydrogen incorporation into the MAX phase Ti 3 AlC 2. International Journal of Hydrogen Energy, 2016, 41 (15), pp.6387 - 6393. ⟨10.1016/j.ijhydene.2016.03.015⟩. ⟨hal-01875451⟩