(278c) Supramolecular Polymer Networks of Ion-Coordinated Polybenzimidazole for High-Temperature H2/CO2 Separation | AIChE

(278c) Supramolecular Polymer Networks of Ion-Coordinated Polybenzimidazole for High-Temperature H2/CO2 Separation

Authors 

Hu, L. - Presenter, University At Buffalo
Fan, S., University of Colorado
Huang, L., University At Buffalo, SUNY
Bui, V., University at Buffalo
Tran, T., University At Buffalo
Pal, S., University At Buffalo
Ding, Y., University of Colorado Boulder
Swihart, M., University at Buffalo
Lin, H., University of Buffalo, State University of New Yor
Membrane technology with superior H2/CO2 separation properties at high temperatures has gained significant attention for pre-combustion CO2 capture. Advanced membrane materials with both high H2 permeability and H2/CO2 selectivity are needed for gas separation to reduce the capital and energy cost. Herein, we demonstrated facilely novel thermally-stable supramolecular polymer networks (SPNs) comprising of metal salt (palladium trifluoroacetate and nickel trifluoroacetate: Pd(CF3COO)2 and Ni(CF3COO)2) and polybenzimidazole (PBI) for H2/CO2 separation at high temperatures. With metal ions coordinating imidazole rings on PBI chains and trifluoroacetate anions unwinding the chain packing, the supramolecular network formed a bottleneck/microcavity bimodal pore architecture, leading to simultaneously increased H2 permeability and H2/CO2 selectivity. Particularly, PBI-Ni(CF3COO)2 supramolecular network with a salt doping level of 0.17 displayed H2 permeability of 62 Barrer at 150 ℃, increased by ~ 100 % from pristine PBI with H2/CO2 selectivity increasing from 10 to 15. Those supramolecular network films also exhibited improved mechanical properties and stable mixed-gas H2/CO2 separation performance at high temperatures. This study unveiled a facile approach to design membrane materials with bottleneck/microcavity bimodal pore architectures, thereby achieving both high gas permeability and selectivity.