Abstract
YMgNi4-based alloys exhibit reversible hydrogen absorption and desorption reactions at near room temperature. Here, we report that Co-substituted YMgNi4-based alloys exhibited higher hydrogen contents and lower hydrogen absorption and desorption reaction pressures than unsubstituted alloys. The effects of Co-substitution viewed from atomic arrangements were particularly clarified by synchrotron radiation powder X-ray diffraction, neutron diffraction, and inelastic neutron scattering. Powder neutron diffraction of the Co-substituted alloy at 5 MPa of D2 pressure suggested the formation of γ-phase deuteride (higher deuterium content) from β-phase deuteride (lower deuterium content). However, no γ-phase deuteride was observed in the unsubstituted alloys at 5 MPa. Therefore, the γ-phase deuteride formation of the Co-substituted alloy at lower pressure led to higher hydrogen contents than the unsubstituted alloys. The combined results of powder neutron diffraction and inelastic neutron scattering suggested that the γ-phase hydride of the Co-substituted alloy was continuously generated due to additional H atoms at the H atom sites in the β-phase hydride because of the disordered H atomic arrangement involving H-H interactions. As a result, hydrogen absorption and desorption reaction pressures for the γ-phase deuteride formation with higher hydrogen storage capacity were lowered.
Original language | English |
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Pages (from-to) | 16943-16951 |
Number of pages | 9 |
Journal | Journal of Physical Chemistry C |
Volume | 126 |
Issue number | 40 |
DOIs | |
State | Published - Oct 13 2022 |
Funding
This research was supported by JST SICORP (JPMJSC 1802), MEXT/JSPS KAKENHI (JP18H05513 and JP18H05518 (“Hydrogenomics”) 19K05051, 22H01817), and the GIMRT Program of the Institute for Materials Research, Tohoku University (Proposal no. 202106-RDKGE-0102). Synchrotron powder X-ray and neutron diffraction were approved by the Photon Factory Program Advisory Committee (proposal no. 2019G572) and the Neutron Science Proposal Review Committee of J-PARC MLF (proposal no. 2019A0068 and 2019B0390). This research benefited from the use of the VISION beamline (IPTS-23889.1) at ORNL’s SNS, supported by the Scientific User Facilities Division, Office of Basic Energy Sciences, U.S. Department of Energy, under contract no. DE-AC0500OR22725. Computational resources were made available through the VirtuES and ICE-MAN projects, funded by the Laboratory Directed Research and Development at ORNL. This research was supported by JST SICORP (JPMJSC 1802), MEXT/JSPS KAKENHI (JP18H05513 and JP18H05518 (“Hydrogenomics”), 19K05051, 22H01817), and the GIMRT Program of the Institute for Materials Research, Tohoku University (Proposal no. 202106-RDKGE-0102). Synchrotron powder X-ray and neutron diffraction were approved by the Photon Factory Program Advisory Committee (proposal no. 2019G572) and the Neutron Science Proposal Review Committee of J-PARC MLF (proposal no. 2019A0068 and 2019B0390). This research benefited from the use of the VISION beamline (IPTS-23889.1) at ORNL’s SNS, supported by the Scientific User Facilities Division, Office of Basic Energy Sciences, U.S. Department of Energy, under contract no. DE-AC0500OR22725. Computational resources were made available through the VirtuES and ICE-MAN projects, funded by the Laboratory Directed Research and Development at ORNL.