High-performance H<sub>2</sub>/CO<sub>2</sub> separation from 4-nm-thick oriented Zn<sub>2</sub>(benzimidazole)<sub>4</sub> films.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 39671495.
- Also identified by DOI 10.1126/sciadv.ads6315 and PMC identifier 11641003.
- 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
High-performance membrane-based H<sub>2</sub>/CO<sub>2</sub> separation offers a promising way to reduce the energy costs of precombustion capture. Current membranes, often made from two-dimensional laminates like metal-organic frameworks, have limitations due to complex fabrication methods requiring high temperatures, organic solvents, and long synthesis time. These processes often result in poor H<sub>2</sub>/CO<sub>2</sub> selectivity under pressurized conditions due to defective transport pathways. Here, we introduce a simple, eco-friendly synthesis of ultrathin, intergrown Zn<sub>2</sub>(benzimidazole)<sub>4</sub> films, as thin as 4 nm. These films are prepared at room temperature using water as the solvent, with a synthesis time of just 10 minutes. By using ultradilute precursor solutions, nucleation is delayed, promoting rapid in-plane growth on a smooth graphene substrate and eliminating defects. These membranes exhibit excellent H<sub>2</sub> permselectivity under pressurized conditions. The combination of rapid, green synthesis and high-performance separation makes these membranes highly attractive for precombustion applications.