Catalytic arene-norbornene annulation (CANAL) ladder polymer derived carbon membranes with unparalleled hydrogen/carbon dioxide size-sieving capability

Precise Hydrogen Sieving by Carbon Molecular Sieve Membranes Derived from Solution-Processable Aromatic Polyamides

“…Note that the mixture permeation showed longer transient time than pure gas CO 2 permeation (Figure S4D in the Supporting Information). Similar phenomena were observed by Hazazi and co-workers in a ladder polymer-derived CMS membrane.…”

“…To our best knowledge, MTI-925 had the highest H 2 /CO 2 ideal selectivity among all known CMS membranes (see Figure D, as well as Table S4 in the Supporting Information), which include those derived from polyimides (Kapton, Matrimid), polyimide-amides (Torlon), PBIs, , PIMs, and cellulose. , Additionally, MTI-925 had competitive H 2 permeability among CMS membranes with H 2 /CO 2 ideal selectivity above 100. Kapton-derived CMS membranes showed comparable H 2 /CO 2 ideal selectivity; however, they were pyrolyzed at higher temperature (1100 °C) and had much lower H 2 permeability (∼0.32 Barrer).…”

“…To our best knowledge, MTI-925 had the highest H 2 /CO 2 ideal selectivity among all known CMS membranes (see Figure 2D, as well as Table S4 in the Supporting Information), which include those derived from polyimides (Kapton, Matrimid), 33 polyimide-amides (Torlon), 34 PBIs, 6,7 PIMs, 4 and cellulose. 35,36 Additionally, MTI-925 had competitive H 2 permeability among CMS membranes with H 2 /CO 2 ideal selectivity above 100.…”

“…As a polymer precursor is pyrolyzed, rigid aromatic strands are formed and organize into defective plates to provide disordered three-dimensional micropores . Many polymer precursors have been studied to fabricate CMS membranes, including polyimides, polymers of intrinsic microporosity (PIMs), , and polybenzimidazoles (PBIs). , By controlling the backbone and bulky side group chemistry of the polymer precursor, the plate defects (i.e., ultramicropores) can be tuned to control molecular discrimination and to obtain attractive gas, − vapor, and liquid separation performance exceeding polymer membranes and many other molecular sieve membranes. Notably, CMS membranes can recover hydrogen (H 2 ) and capture carbon dioxide (CO 2 ) to enable sustainable production of blue H 2 from steam methane reforming .…”

“…Notably, CMS membranes can recover hydrogen (H 2 ) and capture carbon dioxide (CO 2 ) to enable sustainable production of blue H 2 from steam methane reforming. 4 Precise H 2 sieving and outstanding H 2 /CO 2 selectivity is required in H 2 -selective CMS membranes to produce a high-purity H 2 product stream.…”