Influence of crystal size and mesopores connectivity on adsorption/diffusion properties of silicalite-1 crystals

Abstract

SSCI-VIDE+ING+CPG:DLP:ATU:FRM:DFANational audienceIt is well know that the auxiliary network in hierarchical zeolites alleviates diffusional transport limitation. However, the study of connectivity between pores in the secondary network, is not straight forward. Here, we report the influence of the crystal size and the type of additional porosity on the adsorption and diffusion properties of silicalite-1 crystals. We have prepared a series of five model porous silicalite-1 with well controlled mesopore connectivity.The scanning isotherm method by using N2 adsorption/desorption isotherms has been carried out for the determination of possible connections between mesoporous cavities. In addition, the effect of mesopores connections on transport has been measured by DRIFTS and ZLC methods. For instance, we have shown that the transport was mostly limited by surface effects in the case of small crystals, while it was not the case for much larger crystals. The presentation will show correlations between transport and the pore network / size of the crystals