Microporous Cu-based organic frameworks for hydrogen isotope separation†

Deuterium gas is indispensable for various applications, yet the efficient separation of hydrogen isotopes remains a significant challenge. Separation at elevated temperatures using the chemical affinity quantum sieving (CAQS) effect has emerged as a promising strategy. Herein, we systematically investigate the hydrogen isotope gas adsorption and separation properties of two microporous copper-based MOFs, Cu-BTB and Cu-BDC. Comparative analysis reveals that the distinct channel architecture in Cu-BTB substantially governs its hydrogen isotope separation efficiency, suggesting a structure–property correlation in these porous crystalline materials. Theoretical calculations attribute the high adsorption enthalpy of Cu-BTB to the synergistic interplay between its open metal sites and well-defined pore structure. Dynamic gas breakthrough experiments further demonstrate a separation factor of 1.3 at 77 K and 1 bar.