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The good activity and selectivity properties of zeolites are often vanished by diffusion limitations, which can reduce the conversion and increase the rate of catalyst decay. For this reason an increasing attention is addressed to materials that have a hierarchical pore structure, with the aim of minimizing the average diffusion path in the more narrow channels. Recently, trying to optimize the synthesis of the new ERS-10 zeolite, we have obtained different materials exhibiting a very original morphology. The new materials named ERS-10 A, B and A/B, possess slightly different XRD diffraction patterns but completely different morphological and textural properties. ERS-10 B and A/B show a disc-shaped morphology and rather low specific surface area, while ERS-10 A has an interesting specific surface area with a peculiar hierarchical pore structure. It is characterized by a core–shell morphology, in which the shell is formed by a regular epitaxial growth of nanometer-sized NES crystallites on the ERS-10 core, creating a hierarchical pore structure. |
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