The separation of close boiling and azeotropic mixtures of cyclopentane and neohexane is highly challenging in petrochemical industries. Current solutions including azeotropic and extractive distillations require high energy costs and complicated operations. The alternative separation method based on physical adsorption is energy-efficient; however, it has not yet been utilized for the splitting of these two compounds. Herein, we present the kinetic sieving of the abovementioned mixtures by a commercially available zeolite, silicalite-1, which offers intersecting 10-ring channels to promote the adsorption of cyclopentane but possesses steric constraints on the intracrystalline transport of neohexane. In both vapor and liquid phases, the material allows for highly selective separations of cyclopentane/neohexane mixtures under dynamic conditions, which is highly promising for industrial applications.