Table 1. Permeation properties of the single and double-layered ZIF membranes fabricated inside P84 HF supports in the pre-combustion H₂/CO₂ mixture separation. Permeances and separation selectivities at 35 and 150 °C are shown, together with the 99% confidence intervals of each measure. Pure ZIF-9@P84 membrane values were averaged from two different membranes.

	H2 permeance at 35 °C		α H2/CO2	H2 permeance at 150 °C		α H2/CO2
	mol m–2 s–1 Pa–1	GPU		mol m–2 s–1 Pa–1	GPU
ZIF-8/ZIF-9@P84	12.2 ± 2.4 × 10–9	36	5.2 ± 0.7	83.9 ± 0.4 × 10–9	250	9.6 ± 0.1
ZIF-67/ZIF-9@P84	9.9 ± 0.5 × 10–9	29	5.4 ± 0.4	53.3 ± 0.2 × 10–9	159	9.0 ± 0.0
ZIF-9@P84	14.1 ± 3.2 × 10–9	42	4.8 ± 0.1	71.9 ± 0.2 × 10–9	215	8.0 ± 0.1
ZIF-8@P84	11.8 ± 0.1 × 10–9	35	4.1 ± 0.0	65.9 ± 1.1 × 10–9	197	7.4 ± 0.1