High-throughput gas separation by flexible metal-organic frameworks with fast gating and thermal management capabilities.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 32747638.
- Also identified by DOI 10.1038/s41467-020-17625-3 and PMC identifier 7400644.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
Establishing new energy-saving systems for gas separation using porous materials is indispensable for ensuring a sustainable future. Herein, we show that ELM-11 ([Cu(BF<sub>4</sub>)<sub>2</sub>(4,4'-bipyridine)<sub>2</sub>]<sub>n</sub>), a member of flexible metal-organic frameworks (MOFs), exhibits rapid responsiveness to a gas feed and an 'intrinsic thermal management' capability originating from a structural deformation upon gas adsorption (gate-opening). These two characteristics are suitable for developing a pressure vacuum swing adsorption (PVSA) system with rapid operations. A combined experimental and theoretical study reveals that ELM-11 enables the high-throughput separation of CO<sub>2</sub> from a CO<sub>2</sub>/CH<sub>4</sub> gas mixture through adiabatic operations, which are extreme conditions in rapid pressure vacuum swing adsorption. We also propose an operational solution to the 'slipping-off' problem, which is that the flexible MOFs cannot adsorb target molecules when the partial pressure of the target gas decreases below the gate-opening pressure. Furthermore, the superiority of our proposed system over conventional systems is demonstrated.