Ultra-High Purity\nand Productivity Separation of CO<sub>2</sub> and C<sub>2</sub>H<sub>2</sub> from CH<sub>4</sub> in Rigid\nLayered Ultramicroporous Material

Efficiently obtaining both high-purity gas-phase and\nadsorbed-phase\nproducts in a single physisorption process presents the challenge\nof simultaneously achieving high selectivity and uptake and rapid\ndiffusion in adsorbents. With a focus on natural gas purification\nand high-purity acetylene production, we report for the first time\nthat the synergistic ligand/anion binding mode and multiple diffusion\npathways in a robust 2D layered ultramicroporous framework (ZUL-100)\nenable unprecedented carbon dioxide/methane and acetylene/methane\nseparation performance. Taking advantage of its rich anion, functional\nligand ,and rigid 3D interpenetrated ultramicroporous channels, ZUL-100\nachieved record IAST selectivities for equimolar carbon dioxide/methane\n(3.2 × 10<sup>5</sup>) and acetylene/methane (1.7 × 10<sup>10</sup>) mixtures, accompanied by record dynamic uptakes of carbon\ndioxide (3.10 mmol/g) and acetylene (4.79 mmol/g), respectively. The\nstrong affinity and fast mass transfer of carbon dioxide and acetylene\non ZUL-100 were systematically elucidated by a combination of in situ\nFTIR, single-crystal XRD, kinetic tests, and DFT-D adsorption/diffusion\nmodeling. In particular, high-purity (≥99.999%) methane and\ncarbon dioxide (acetylene) can both be obtained on ZUL-100 through\na single adsorption–desorption cycle, with exceptional productivity\n(2.81–4.22 mmol/g of methane, 2.96 mmol/g of carbon dioxide,\nand 4.31 mmol/g of acetylene) and high yield (95.5% for carbon dioxide\nand 90.0% for acetylene).