Lithium-Modified UiO-66–2OH for Improved D ₂ /H ₂ Separation Performance

Efficient separation of hydrogen isotopes (D₂/H₂) is critically important for applications such as nuclear fusion, but it remains highly challenging due to their nearly identical physicochemical properties. In this work, a scalable UiO-66-2OH metal-organic framework was synthesized via a simple and low-cost method and further modified through Li⁺ loading to enhance its performance. The optimized 0.1Li⁺@UiO-66-2OH exhibits improved D₂/H₂ adsorption and separation behavior, as demonstrated by both equilibrium adsorption and dynamic breakthrough experiments, showing an effective D₂ enrichment and purification capability. Spectroscopic analyses (FT-IR and XPS) suggest interactions between the introduced Li⁺ sites and the framework oxygen atoms, which contribute to the enhanced affinity for hydrogen isotopes. To evaluate its practical applicability, the material was further processed into granulated samples, which maintain effective D₂/H₂ separation performance at 100 and 120 K. This work demonstrates a feasible strategy for improving hydrogen isotope separation in MOF-based materials and highlights their potential for practical isotope enrichment applications.