New Material for Deuterium Separation at Higher Temperatures
A novel porous material capable of separating deuterium from hydrogen at a temperature of 120 K (-153°C) has been introduced. This opens a pathway for sustainable industrial-scale isotope separation using existing liquefied natural gas (LNG) infrastructure.
Isotopes have the same number of protons and electrons, differing only in the number of neutrons. Deuterium (D2) is a stable isotope of hydrogen (H2) and plays a critical role in several domains, from energy production to the electronics industry.
However, separating hydrogen isotopes in industrial processes poses challenges, as traditional methods require extremely low temperatures (e.g., cryogenic distillation is conducted at temperatures as low as 20 K, or -253°C) and are notorious for their high energy consumption and operational inefficiencies.
The crystal structure of the copper-based zeolite imidazolate framework (Cu-ZIF-gis ) studied for the separation of hydrogen isotopes (H₂/D₂)
Recently, confined porous systems such as metal-organic frameworks (MOFs) – advanced materials with exceptional porosity and a chemical versatility that enables their properties to be tuned to meet the requirements of a wide range of applications – have emerged as efficient methods for hydrogen isotope separation (through nuclear quantum effects). However, efficiency tends to diminish significantly as temperature increases.
A study now published in Nature Communications presents a new, copper-based MOF that shows exceptional D2 separation performance, even at 120 K (-153℃). Confirmatory in-situ X-ray diffraction (XRD) and quasi-elastic neutron scattering (QENS) experiments were conducted at the ILL by a joint team of researchers from Ulsan National Institute of Science and Technology and Soongsil University (Republic of Korea), the Helmholtz-Zentrum Berlin für Materialien und Energie (HZB) and Heinz Maier Leibnitz Zentrum (MLZ), Germany.
At cryogenic temperatures, the pores of the developed MOF are smaller than H2 molecules, thereby inhibiting their passage. However, as the temperature increases, the lattice expands, leading to an increase in pore size. This enlargement facilitates the passage of gases through the pores, thereby enabling the separation of H2 and D2.
QENS experiments confirmed the expansion of the lattice framework with increasing temperature, as well as a notable difference in the molecular mobility of H2 and D2, even at temperatures exceeding 150 K. QENS measurements were carried out on the time-of-flight (TOF) spectrometer IN5. During QENS measurement, H2 and D2 gases were injected into the sample, at each temperature (77 K–150 K) through an in situ gas dosing system.
In conclusion, this material exhibits enhanced separation efficiency and markedly lower energy consumption compared to most traditional methods. These findings can be applied to develop sustainable isotope separation technologies using existing LNG cryogenic infrastructure, underscoring its potential industrial impact.
The press release issued by UNIST can be found on their website.
Reference: Minji Jung, Jaewoo Park et al., Lattice-driven gating in a Cu-based zeolitic imidazolate framework for efficient high-temperature hydrogen isotope separation, Nat. Commun.16, 2032 (2025). DOI: 10.1038/s41467-025-56649-5
ILL instruments: IN5
ILL contacts: Jacques Ollivier