Fig. 6: Molecular dynamics simulations on the diffusion of propene and 1-butene molecules in MFI-structured zeolite.

a MSDs of propene diffusion in different directions at different temperatures. b MSDs of 1-butene diffusion in different directions at different temperatures. c The ratio of self-diffusion coefficient in x- and y-directions. d Schematic view of olefin molecules diffusion along x- and y-directions of MFI-type zeolites. The anisotropic components MSDxx, MSDyy, and MSDzz curves were calculated by three individual samples, and the average MSD, Dself-xx, and Dself-yy are reported in this work.