INS6-1630
Polybenzimidazole-based Membranes for Sustainable Hydrogen Production and Gas Separation
Topic
S6. Emerging Polymer and Hybrid Materials for Advanced Energy Storage and Conversion
When and Where
Sep 29, 2026
16:40 - 17:05
Room 311 & 312
Session Chairs
Young Jun LEE
Presenter(s)
Jong Geun Seong (Korea Institute of Science and Technology (KIST))
Co-Author(s)
Abstract
Polybenzimidazoles (PBIs) are a class of heteroaromatic polymers with high thermal and chemical stability, strong intermolecular hydrogen bonding, and versatile interactions with acids and bases. These characteristics make PBI a promising platform for membranes used throughout the hydrogen value chain. This presentation discusses two representative membrane applications for energy-efficient hydrogen production, and gas separation. First, para-PBI was applied as an ion-solvating and hydrogen-barrier layer in a thin-film-assembled membrane for anion exchange membrane water electrolysis. The rigid, hydrogen-bonded PBI chains suppressed hydrogen crossover, while KOH uptake enabled hydroxide-ion transport. A multilayer membrane composed of p-PBI, Zirfon, and an anion-exchange polymer achieved 3.93 A cm⁻² at 2.0 V in 30 wt% KOH at 90 °C, reduced hydrogen permeance from 2.5 to 0.23 GPU relative to Zirfon, and demonstrated stable operation for more than 1,670 h at high current densities. Second, PBI-derived carbon molecular sieve hollow fiber membranes were developed for elevated-temperature H₂/CO₂ separation. Precursor crosslinking and controlled pyrolysis preserved an asymmetric hollow-fiber structure consisting of an ultrathin selective layer and a porous support. The optimized membrane, pyrolyzed at 700 °C, exhibited an H₂ permeance of 100 GPU and an ideal H₂/CO₂ selectivity of 80, while maintaining stable separation performance for approximately 850 h under humidified simulated syngas conditions. These results demonstrate that PBI can be engineered as either a molecular-sieving separation medium or an ion-conducting gas-barrier membrane, providing a versatile polymer platform for sustainable hydrogen technologies.
