High-performance H2/CO2 separation from 4-nm-thick oriented Zn2(benzimidazole)4 films

• Published in: Science advances 2024-12, Vol.10 (50), p.eads6315
• Main Authors: Song, Shuqing, Liu, Qi, Swathilakshmi, S, Chi, Heng-Yu, Zhou, Zongyao, Goswami, Ranadip, Chernyshov, Dmitry, Agrawal, Kumar Varoon
• Format: Article
• Language: English
• ISSN: 2375-2548; 2375-2548
• DOI: 10.1126/sciadv.ads6315

High-performance membrane-based H2/CO2 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 H2/CO2 selectivity under pressurized conditions due to defective transport pathways. Here, we introduce a simple, eco-friendly synthesis of ultrathin, intergrown Zn2(benzimidazole)4 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 H2 permselectivity under pressurized conditions. The combination of rapid, green synthesis and high-performance separation makes these membranes highly attractive for precombustion applications.High-performance membrane-based H2/CO2 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 H2/CO2 selectivity under pressurized conditions due to defective transport pathways. Here, we introduce a simple, eco-friendly synthesis of ultrathin, intergrown Zn2(benzimidazole)4 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 H2 permselectivity under pressurized conditions. The combination of rapid, green synthesis and high-performance separation makes these membranes highly attractive for precombustion applications.