Acid-Catalyzed Interfacial Polymerization of a Benzimidazole-Linked Polymer Membrane for Efficient H<sub>2</sub>/CO<sub>2</sub> Separation
Jingjing Zhang, Chaoqun Niu, Ning Ren, Juan Du, Meixia Shan, Roberto Castro‐Muñoz, Yatao Zhang
Abstract
The development of cost-effective and energy-efficient membrane materials is of significant importance for the purification of hydrogen and the capture of carbon dioxide. Given the potential of benzimidazole-linked polymers (BILPs) for H 2 /CO 2 separation, this study aimed to synthesize a novel BILP membrane material (BILP-x) through an acid-catalyzed interfacial polymerization strategy. The BILP-x membranes achieved an exceptional H 2 permeance of 176.6 GPU and a H 2 /CO 2 selectivity of 12.3 at room temperature. Decreasing the BTA concentration can significantly increase the H 2 permeance to 987.6 GPU, while the H 2 /CO 2 selectivity decreased to 8.0 at room temperature. In addition, the BILP-x membrane demonstrated exceptional long-term stability in H 2 /CO 2 separation, maintaining its performance for up to 300 h under alternating temperatures of 373 and 423 K. Meanwhile, the molecular dynamics simulations verified that the addition of acid accelerated the diffusion rate of TP molecules in the interfacial polymerization reaction, resulting in the formation of denser membranes. The finding not only validates the promise of BILP-x membranes for H 2 /CO 2 separation, but also opens up a new avenue for the development of high-performance membrane materials for a range of separation applications.