Cost‐Effective Scalable Production of Ultra‐Stable Alkyl MOF Featuring Single‐Molecule C ₃ H ₆ Trap for Record Capture of Trace C ₃ H ₆ from C ₂ H ₄

Highly efficient capture of trace C₃H₆ from C₂H₄ by physisorbents remains an enormous challenge to combine top-rank separation performance with excellent stability and economical scalability. We, herein, built a single-molecule C₃H₆ trap that bears an opposite series of oxygen and dense alkyl groups distributed in an ultramicroporous [Al(OH)(trans-CDC)] (Al-CDC, trans-H₂CDC = trans-1,4-cyclohexanedicarboxylic acid). The ultra-stable trap with well-matched pore size and pore chemistry enables a record uptake (40.8 cm³(STP) g^-1) at ultralow concentration, Henry coefficient (12685.5 cm³(STP) g^-1 bar^-1), initial adsorption heat difference (27.2 kJ mol^-1), adsorption kinetic (0.49 min^-1) and kinetic selectivity (3.1) for C₃H₆ with one of the highest initial C₃H₆ adsorption heats (50.5 kJ mol^-1) and selectivity (16.3), establishing a novel benchmark for capture of trace C₃H₆. The C₃H₆ adsorption mechanism is deciphered to be thermodynamically driven owing to the synergism of multiple hydrogen-bonding and van der Waals (vdW) forces. Breakthrough tests validate that Al-CDC owns a record C₂H₄ productivity (≥99.999%) of 410.5 cm³(STP) g^-1 for trace C₃H₆ capture with excellent reproducibility. The cost-effective scalable production with the cheapest cost (508.9 $ kg^-1) and highest space-time yield (4564.8 kg m^-3 day^-1) and shaping of Al-CDC is realized with unaffected structural property and capture performance.