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An exact knowledge of the architecture of complex pore networks and the impact on transport processes is critical to understand and optimize their integration in many functional solids. Here, a robust and versatile approach is demonstrated to quantitatively map pore constrictions within hierarchical faujasite-type (Y and USY) zeolites, the most widely applied zeolitic materials in industry. Differential hysteresis scanning measurements by high-resolution argon sorption coupled with an advanced modeling framework enable the derivation of the amount and size of pyramidal, constricted, and occluded mesopores. This yields unprecedented insight into the impact of widely practiced demetallation treatments on the porosity evolution and clearly highlights the interplay between the geometry of mesopores developed by a given treatment and those introduced by previously applied postsynthetic modifications. Based on the findings, the dynamic assessment by positron annihilation spectroscopy confirms the effectiveness of each mesopore type at enhancing the diffusion of ortho-positronium within the crystal. The quantitative descriptors attained by these complementary techniques can revolutionize the design of porous materials for a wide range of applications. [ABSTRACT FROM AUTHOR]

Mass transfer in zeolite crystals can be enhanced by the introduction of a hierarchical network of auxiliary mesopores. To fully exploit pore engineering in the design of more efficient industrial catalysts, the benefit needs to be demonstrated over technically relevant forms. Here, the influence of shaping on the adsorption and diffusion properties of hierarchical ZSM‐5 is assessed by studying the gravimetric uptake of 2,2‐dimethylbutane over powders and millimeter‐sized bodies. Formed by extrusion or granulation with clay binders, the latter display a complex trimodal network of micro‐, meso‐, and macropores. The enhanced intracrystalline diffusivity due to the interconnected mesopores is preserved in the macroscopic bodies, independent of the shaping method or binder applied. Furthermore the superior overall diffusivity is retained in the hierarchical bodies compared to their conventional (purely microporous) counterparts, despite the significant extracrystalline resistance to mass transfer. The connective participation of mesopores, leading to a 6 times improved effective diffusivity in hierarchical with respect to conventional zeolite powders, is revealed by the distinct dependence on the adsorbate concentration and the relationship with the mesopore surface area. Analysis of the thermodynamic parameters derived from the adsorption isotherm proves a sensitive method to detect binder‐zeolite interactions induced upon shaping. [ABSTRACT FROM AUTHOR]

On page 5621, J. Kenvin, J. Pérez‐Ramírez, and coworkers demonstrate differential hysteresis scanning by high‐resolution argon sorption and positron annihilation spectroscopy as powerful tools to quantify the complex architecture of pore networks in hierarchical faujasite zeolites and their efficiency in transport processes. The descriptors attained by these complementary techniques further advance the design of porous materials for a wide range of applications. The creatures in the cover, exploring a tortious cave system, exemplify the challenges with pore accessibility and connectivity. [ABSTRACT FROM AUTHOR]