Screening of Metal-Organic Frameworks for Highly Effective Hydrogen Isotope Separation by Quantum Sieving

Separation of hydrogen isotopes is of great importance to produce highly pure hydrogen isotopes for numerous applications, which is however very difficult because of their almost identical thermodynamic properties. Adsorptive separation is considered as a simple, highly efficient, and cost-effective technique compared to the traditional methods, where the key is the suitable adsorbent. Herein, SIFSIX-3-Zn was screened out from the reported metal-organic frameworks (MOFs), exhibiting high selectivities for a D₂/H₂ mixture by quantum sieving effect. Advanced cryogenic thermal desorption spectroscopy confirms the calculation results, indicating that the selectivities for a 1:1 D₂/H₂ mixture at 20 K are larger than the values reported so far; especially, it shows a record value of 53.8 at 25 kPa. This demonstrates that this MOF is a promising candidate for highly effective hydrogen isotope separation.