This study systematically investigates the separation performance of porous \(\gamma\) - \(Al_2\) \(O_3\) for neon isotopes ( \(^{20}Ne\) / \(^{22}Ne\) ) under cryogenic conditions through molecular dynamics (MD) simulations. By constructing \(\gamma\) - \(Al_2\) \(O_3\) models with varying pore sizes (4.5–15 Å) and performing MD simulations, the critical effects of pore size and temperature on separation factors are revealed. The results demonstrate that \(\gamma\) - \(Al_2\) \(O_3\) with sub-6 Å pore size exhibits remarkable isotopic sieving capability under a fixed pore volume of 0.6 \(\hbox {cm}^3/\hbox {g}\) . Specifically, the 4.5 Å pore-sized material achieves a separation factor of 1.333 at 30 K, indicating preferential kinetic selectivity for \(^{20}Ne\) . Reduced temperatures significantly enhance separation performance, provided that the pore size is sub-10 Å. The diffusion coefficient’s dependence on both temperature and pore diameter follows the Knudsen diffusion mechanism. This research establishes that microporous \(\gamma\) - \(Al_2\) \(O_3\) enables effective neon isotope separation through combined molecular sieving and kinetic discrimination effects, offering theoretical foundations for developing advanced neon isotope-selective materials.
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