Nanoconfinement‐enabled selective trapping of trace propane in a shaped Al‐ MOF for ultra‐pure fluoromethane

Abstract Ultrahigh‐purity fluoromethane (CH 3 F) is essential for sustainable semiconductor manufacturing, yet its deep purification poses a significant challenge due to trace amounts of propane (C 3 H 8 ). Herein, a shaped Al‐based MOF, Al‐Fum, was engineered as high‐performance adsorbents to address this solution. The adsorbent features a tailored pore aperture (~5.6 × 6.0 Å) that provides an optimal nanoconfined environment for C 3 H 8 molecular discrimination. Owing to the higher polarizability of C 3 H 8 , a pronounced confinement‐enhanced induction interaction is selectively activated within the weakly polar channels, leading to exceptional separation selectivity. The C 3 H 8 concentration is thereby reduced from 100 ppm to the part‐per‐trillion level in the CH 3 F stream. Robust Al‐Fum pellets were produced via a scalable shaping method that retains the intrinsic adsorption performance. Their stability and regenerability are confirmed by dynamic breakthrough tests. This work elucidates a polarizability‐driven nanoconfinement mechanism and delivers a readily applicable adsorbent for next‐generation electronic‐gas purification.