Fig. 3. Gas transport performance.

a, b Gas permeability (a) and ideal selectivity (b) in MMMs as a function of filler content at 35 °C and 3.5 bar. Error bars represent the standard deviations obtained from three membranes; c, d Diffusivity (c) of CO₂, N₂, and CH₄, and sorption and diffusion selectivity (d) of CO₂/N₂, CO₂/CH₄ in PIM-1, Z-5-1, and H-5-1. Error bars represent the standard deviations obtained from three membranes; e Normalized CO₂ permeability of PIM-1 and H-5-1 membranes with CO₂ feed pressure increasing from 3.5 to 20 bar; f Comparison of the CO₂ permeability versus CO₂/N₂ selectivity improvement for PIM-1/MOF MMMs in the literature with the optimal result in this study. The blue dots represent the data from references, as listed in Supplementary Table 7, and the red star represents the H-5-1 membrane. Source data are provided as a Source Data file; g Cross-sectional SEM image of the H-5-1 thin-film membrane on the surface of PI support. The inserted picture is the corresponding macro digital photo (Scale bar: 1 μm); h Ageing behavior of PIM-1, Z-5-1, and H-5-1 thin-film membranes. The samples are directly exposed to the atmosphere during the test interval.