ASSESSMENT OF MASS TRANSPORT PROPERTIES IN BIMODAL MICROPOROUS NETWORKS BY COMBINING GRAVIMETRIC AND INFRARED SPECTROSCOPY

International audienceInterest of this study is to develop classical macroscopic diffusion measurements to probe and allow distinguishing a true hierarchical material from the other material. To this aim, the AGIR methodology (Analysis by Gravimetry and IR spectroscopy) will be used Gravimetric measurements provide more classical approach to molecular uptake measurements, whereas infrared (IR) spectroscopy can provide additional data on the interaction, orientation and environment of the molecules on the solid surfaces. In this study we evaluated the mass transport properties in a mechanical mixture of hierarchical H-MFI and H-FAU zeolites. Using AGIR technique, we have been able to distinguish the diffusivity of each component present in the mechanical mixture of following pure zeolites: H-MFI and H-FAU respectively. The potential and limitations of this new methodology will be discussed

Unraveling the Diffusion Properties of Zeolite-Based Multicomponent Catalyst by Combined Gravimetric Analysis and IR Spectroscopy (AGIR)

International audienceThe concept of pore hierarchization for enhancing zeolite catalytic performance has been the main focus during the past decade; the main research activities have widely emphasized the preparation of single-component hierarchical zeolite catalysts. Here we report on the critical aspect of interconnectivity of multicomponents in hierarchical zeolite catalysts using a combined gravimetric and infrared spectroscopy (AGIR) analysis. The variances of macroscopic diffusion behaviors between the global multicomponent catalyst (indexed as global diffusion time constant) and its zeolitic moiety (indexed as micropore diffusion time constant) are differentiated via simultaneous gravimetric and infrared analysis, respectively. The effectiveness factors correlated with the diffusion time constants show that the nonideal interconnectivity between the zeolitic and nonzeolitic components weakens the full potential of the multicomponent catalyst