Mesoporous MOF NU-1000 as a High-Efficiency HPLC Stationary Phase: Transport-Controlled Design and Quantitative Evaluation

Metal–organic frameworks (MOFs) offer structurally precise and chemically programmable pore environments for chromatographic separations, yet their implementation as high-performance liquid chromatography (HPLC) stationary phases remains limited by insufficient control over particle morphology and mass transport. Here, we report a transport-focused evaluation of the mesoporous Zr-based MOF NU-1000 as an HPLC stationary phase. Micrometer-sized NU-1000 particles were prepared by modulator-assisted synthesis, and pore accessibility was systematically varied by comparing a benzoate-coordinated framework with its acid-treated, pore-open analogue. Reduced van Deemter and Péclet-number analyses reveal that the pore-open NU-1000 phase provides substantially improved column kinetics, reaching a minimum reduced plate height of hmin = 4.68 and plate numbers up to N = 3334 on a 50 mm column. Under matched-retention conditions, NU-1000 outperforms a self-packed C18 reference and approaches the performance of a commercially packed C18 benchmark, despite its rod-shaped particle morphology. The practical resolving power of NU-1000 is further demonstrated by gradient separation of PEG 400, where discrete polymer homologues are resolved with monomer-unit precision and a peak capacity of 213.7. These results establish pore accessibility and particle size as key design parameters for MOF-packed HPLC columns and demonstrate that bare mesoporous MOF particles can directly deliver high packed-bed efficiencies exceeding 60,000 plates m–1, without relying on core–shell architectures, hierarchical composites, or capillary-column formats.