Suprasilica Nanosieves for Selective Capture of Aromatics Over Cyclic Aliphatics in Hydrocarbon Feedstocks

ABSTRACT Separating aromatic from cyclic aliphatic hydrocarbons remains a major challenge, as conventional distillation is both energy‐intensive and poorly selective. Here, we report supramolecular silica nanosieves (suprasilica) that integrate organic molecular recognition sites directly into robust inorganic matrices. A hexasila‐ureido‐trianglamine (Δ‐Si 6 ) is co‐condensed within the silica matrix through a self‐assembly sol–gel approach at controlled loadings to produce suprasilica sieves ( Δ‐SiN x ). In vapor sorption, Δ‐SiN x reject cyclic aliphatic hydrocarbons while displaying high aromatic uptake, achieving benchmark ideal selectivity for benzene over cyclohexane (23.5, uptake 9.4 mmol g − 1 ) on Δ‐SiN20 and for toluene over methylcyclohexane (6.3, uptake 6.3 mmol g − 1 ) on Δ‐SiN10 . The selectivity was further confirmed by Dynamic Column Breakthrough experiments, which demonstrated efficient separation under dynamic conditions. Importantly, the Δ‐SiN x retain their molecular discrimination in the binary liquid phase, showing strong preferential uptake while preserving aromatic selectivity in neat naphtha and in diluted crude oil. Metadynamics simulations indicate that the selectivity is kinetic in origin, benzene passing the macrocyclic apertures with a modest barrier while cyclohexane is excluded. These suprasilica nanosieves deliver benchmark separation performance and provide a scalable, energy‐efficient strategy for hydrocarbon purification.