Rapid diffusion of H 2 and strong adsorption of D 2 in Ni-4PyC realized the efficient separation of H 2 /D 2 by gas chromatography.

In this work, Ni-4PyC was selected as the material for the separation of hydrogen isotopes H 2 /D 2 , and the mechanism of hydrogen isotope H 2 /D 2 separation was investigated by molecular simulation. The results showed that the adsorption selectivity of Ni-4PyC for D 2 /H 2 increased from 1.26 to 1.46 when the temperature was decreased from 77 K to 20 K, indicating that Ni-4PyC effected chemical affinity quantum sieving on D 2 /H 2 . Also, the diffusion rates of H 2 /D 2 were different at different temperatures. At 20 K, the kinetic selectivity of D 2 /H 2 reached 1.30, indicating that Ni-4PyC had a kinetic quantum sieving effect on D 2 /H 2 at low temperatures. However, when the temperature was higher than 30 K, the diffusion rate of H 2 was faster than that of D 2 , and when the temperature was 77 K, Ni-4PyC exhibited the kinetic sieving effect with a kinetic selectivity of 1.59 for H 2 /D 2 . Due to the chemical affinity quantum sieving and kinetic sieving effects of Ni-4PyC on H 2 /D 2 , the adsorption capacity of Ni-4PyC for D 2 was better than that for H 2 and the diffusion rate of H 2 was faster than that of D 2 at 77 K. Therefore, Ni-4PyC was expected to achieve the separation of H 2 /D 2 . In order to verify the accuracy of the theoretical calculation results, an Ni-4PyC@γ-Al 2 O 3 composite material was synthesized by a liquid phase epitaxy method and was used to separate H 2 /D 2 at 77 K in a 0.6 m × 2 mm chromatographic column. Under optimal separation conditions, the resolution R reached 1.84 with a separation time t = 7.47 min. In addition, Ni-4PyC@γ-Al 2 O 3 showed excellent separation performances for different ratios of H 2 /D 2 mixtures. The stationary phase was repeatable and reproducible.