Metal-organic framework/graphene nanoribbon/polyimide mixed-matrix membranes for high-temperature H<sub>2</sub>/N<sub>2</sub> separation.

So, Soon Hyeong; Kim, Sunwoo; Kim, Minsu; Kim, Donghyun; Kim, Taehwan; Eum, Kiwon; Kim, Yun Ho; Kim, Junghwan et al. · Sci Adv · 2026

basic_science · Level V

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Abstract

We report the application of mixed-matrix membranes for high-temperature hydrogen separation. To enhance hydrogen selectivity, graphene nanoribbons (GNRs) were incorporated into ZIF-8 fillers, forming a physically confined structure conducive to hydrogen transport. The metal-organic framework (MOF)/GNR filler embedded into a polyimide (PI) matrix yielded a much higher H<sub>2</sub> permeability (298 Barrer, +40%) and H<sub>2</sub>/N<sub>2</sub> selectivity (15, +25%) than the neat PI membrane. In particular, the as-prepared asymmetric membrane achieved a H<sub>2</sub> permeance of 212 ± 45 Gas Permeation Unit (GPU) and H<sub>2</sub>/N<sub>2</sub> selectivity of 19 ± 2 at 35°C. Remarkably, at 300°C, the H<sub>2</sub> permeance rose to 775 ± 139 GPU while maintaining a H<sub>2</sub>/N<sub>2</sub> selectivity of 13 ± 1, outperforming polymer-based membranes. A techno-economic analysis of an NH<sub>3</sub> cracking process demonstrated that this high permeance reduces membrane area requirements by 68.2% and lowers H<sub>2</sub> separation costs by 35.1% compared with operation at 35°C, leading to a 9.8% reduction in the levelized cost of hydrogen.