Ultra-High Purity and Productivity Separation of CO<sub>2</sub> and C<sub>2</sub>H<sub>2</sub> from CH<sub>4</sub> in Rigid Layered Ultramicroporous Material
Yuanyuan Jin, Tian Ke, Guihong Xu, Jinjian Li, Zhixin Jiang, Rongrong Fan, Zhiguo Zhang, Zongbi Bao, Qilong Ren, Qiwei Yang
Abstract
High Resolution Image Download MS PowerPoint Slide Efficiently obtaining both high-purity gas-phase and adsorbed-phase products in a single physisorption process presents the challenge of simultaneously achieving high selectivity and uptake and rapid diffusion in adsorbents. With a focus on natural gas purification and high-purity acetylene production, we report for the first time that the synergistic ligand/anion binding mode and multiple diffusion pathways in a robust 2D layered ultramicroporous framework (ZUL-100) enable unprecedented carbon dioxide/methane and acetylene/methane separation performance. Taking advantage of its rich anion, functional ligand,and rigid 3D interpenetrated ultramicroporous channels, ZUL-100 achieved record IAST selectivities for equimolar carbon dioxide/methane (3.2 × 10 5 ) and acetylene/methane (1.7 × 10 10 ) mixtures, accompanied by record dynamic uptakes of carbon dioxide (3.10 mmol/g) and acetylene (4.79 mmol/g), respectively. The strong affinity and fast mass transfer of carbon dioxide and acetylene on ZUL-100 were systematically elucidated by a combination of in situ FTIR, single-crystal XRD, kinetic tests, and DFT-D adsorption/diffusion modeling. In particular, high-purity (≥99.999%) methane and carbon dioxide (acetylene) can both be obtained on ZUL-100 through a single adsorption–desorption cycle, with exceptional productivity (2.81–4.22 mmol/g of methane, 2.96 mmol/g of carbon dioxide, and 4.31 mmol/g of acetylene) and high yield (95.5% for carbon dioxide and 90.0% for acetylene).