Extended Data Fig. 2: Diffusion-rate measurements of propane or propylene in 0.25%Pt–Sn@S-1.

a–c, The uptake curves of propane in 0.25%Pt–Sn@S-1(0.10 μm), 0.25%Pt–Sn@S-1(0.50 μm) and 0.25%Pt–Sn@S-1(4.00 μm) at 25, 40, 55 and 70 °C (0 → 20 mbar), respectively (details of this figure are summarized in Supplementary Table 14). d–f, The uptake curves of propylene at 25, 40, 55 and 70 °C (0 → 20 mbar) in 0.25%Pt–Sn@S-1(0.10 μm), 0.25%Pt–Sn@S-1(0.50 μm) and 0.25%Pt–Sn@S-1(4.00 μm), respectively (details of this figure are summarized in Supplementary Table 14). g, The inverse of diffusion time constant of propane in 0.25%Pt–Sn@S-1(0.10 μm), 0.25%Pt–Sn@S-1(0.50 μm) and 0.25%Pt–Sn@S-1(4.00 μm), respectively. The error bar is the error of fitting between experimental data and the theoretical model. h, The inverse of diffusion time constant propylene in 0.25%Pt–Sn@S-1(0.10 μm), 0.25%Pt–Sn@S-1(0.50 μm) and 0.25%Pt–Sn@S-1(4.00 μm), respectively. The error bar is the error of fitting between experimental data and theoretical model. i, The uptake curves of propane in 0.25%Pt–Sn@S-1(4.00 μm) with different loading qualities. Notes: it should be emphasized that the effect of external diffusion was eliminated by changing the quality of samples shown in panel i. The details of uptake curves fitting are listed in Supplementary Tables 15 and 16. It can be noticed that the coefficient of determination of fitting R² by the dual resistance model (DRM) for all uptake curves measured in this work is above 0.95, which confirms the feasibility and acceptable fitting error of the DRM in fitting uptake curves (panels a–f). In theory, the DRM takes the intracrystalline diffusion and surface barriers as two dominated mass-transport mechanisms in the samples based on the assumption of uniform crystal-size distribution. In practice, the fitting errors between the DRM and experiments can be affected by the non-uniform size distribution of samples⁴² and the adsorption-dependent diffusion rate of guest molecules in different samples⁴³.