Computational design of novel MAX phase alloys as potential hydrogen storage media combining first principles and cluster expansion methods. Issue 6 (31st January 2023)

• Record Type: Journal Article
• Authors: Das, Pritam; Thekkepat, Krishnamohan; Lee, Young-Su; Lee, Seung-Cheol; Bhattacharjee, Satadeep
• Is Part Of: Physical chemistry chemical physics. Volume 25:Issue 6(2023)
• Page Start: 5203
• Page End: 5210
• Publication Date: 2023-01-31
• Subjects: Chemistry, Physical and theoretical -- Periodicals; 541.3
• DOI: 10.1039/d2cp05587b
• Languages: English
• ISSNs: 1463-9076

Abstract

Abstract : Transition metal doped MAX phase alloy as a novel hydrogen storage media. Abstract : Finding a suitable material for hydrogen storage under ambient atmospheric conditions is challenging for material scientists and chemists. In this work, using a first principles based cluster expansion approach, the hydrogen storage capacity of the Ti2 AC (A = Al, Ti, Cr, Mn, Fe, Co, Ni, Cu, and Zn) MAX phase and its alloys was studied. We found that hydrogen is energetically stable in Ti–A layers in which the tetrahedral site consisting of one A atom and three Ti atoms is energetically more favorable for hydrogen adsorption than other sites in the Ti-A layer. Ti2 CuC has the highest hydrogen adsorption energy than other Ti2 AC phases. We find that the 83.33% Cu doped Ti2 Al x Cu1− x C alloy structure is both energetically and dynamically stable and can store 3.66 wt% hydrogen under ambient atmospheric conditions, which is higher than that stored by both Ti2 AlC and Ti2 CuC phases. These findings indicate that the hydrogen capacity of the MAX phase can be significantly improved by doping an appropriate atom species.