Ultramicroporous material based parallel and extended paraffin nano-trap for benchmark olefin purification

Selective paraffin capture from olefin/paraffin mixtures could afford high-purity olefins directly, but suffers from the issues of low separation selectivity and olefin productivity. Herein, we report an ultramicroporous material (PCP-IPA) with parallel-aligned linearly extending isophthalic acid units along the one-dimensional channel, realizing the efficient production of ultra-high purity C2H4 and C3H6 (99.99%). The periodically expanded and parallel-aligned aromatic-based units served as a paraffin nano-trap to contact with the exposed hydrogen atoms of both C2H6 and C3H8, as demonstrated by the simulation studies. PCP-IPA exhibits record separation selectivity of 2.48 and separation potential of 1.20 mol/L for C3H8/C3H6 (50/50) mixture, meanwhile the excellent C2H6/C2H4 mixture separation performance. Ultra-high purity C3H6 (99.99%) and C2H4 (99.99%) can be directly obtained through fixed-bed column from C3H8/C3H6 and C2H6/C2H4 mixtures, respectively. The record C3H6 productivity is up to 15.23 L/kg from the equimolar of C3H8/C3H6, which is 3.85 times of the previous benchmark material, demonstrating its great potential for those important industrial separations. Selective paraffin capture to afford high-purity olefins directly is critical but still challenging. Herein, the authors discover a distinctive ultramicroporous material featuring closely packed and linearly-extended isophthalic acid units and thus serving as a paraffin nano-trap for the efficient production of ultra-high purity olefins from paraffins.