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Elucidation of Diffusivity of Hydrogen Isotopes in Flexible MOFs by Quasi‐Elastic Neutron Scattering
Author(s) -
Jung Minji,
Park Jaewoo,
Muhammad Raeesh,
Kim Jin Yeong,
Grzimek Veronika,
Russina Margarita,
Moon Hoi Ri,
Park Jitae T.,
Oh Hyunchul
Publication year - 2021
Publication title -
advanced materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 10.707
H-Index - 527
eISSN - 1521-4095
pISSN - 0935-9648
DOI - 10.1002/adma.202007412
Subject(s) - materials science , deuterium , isotope , thermal diffusivity , hydrogen , chemical physics , neutron scattering , diffusion , kinetic isotope effect , kinetic energy , isotope separation , neutron , chemical engineering , atomic physics , thermodynamics , chemistry , nuclear physics , organic chemistry , physics , quantum mechanics , engineering
Abstract Kinetic‐quantum‐sieving‐assisted H 2 :D 2 separation in flexible porous materials is more effective than the currently used energy‐intensive cryogenic distillation and girdle‐sulfide processes for isotope separation. It is believed that material flexibility results in a pore‐breathing phenomenon under the influence of external stimuli, which helps in adjusting the pore size and gives rise to the optimum quantum‐sieving phenomenon at each stage of gas separation. However, only a few studies have investigated kinetic‐quantum‐sieving‐assisted isotope separation using flexible porous materials. In addition, no reports are available on the microscopic observation of isotopic molecular transportation during the separation process under dynamic transition. Here, the experimental observation of a significantly faster diffusion of deuterium than hydrogen in a flexible pore structure, even at high temperatures, through quasi‐elastic neutron scattering, is reported. Unlike rigid structures, the extracted diffusion dynamics of hydrogen isotopes within flexible frameworks show that the diffusion difference between the isotopes increases with an increase in temperature. Owing to this unique inverse trend, a new strategy is suggested for achieving higher operating temperatures for efficient isotope separation utilizing a flexible metal–organic framework system.