This study presents a series of Interzeolite Transformation Intermediates (ITIs) derived from FAU-to-FER interconversion. These hybrid materials, obtained through precise control of the interconversion process, exhibit both large mesoporosity and FER topology-type pore confinement, resulting in high conversion and remarkable shape selectivity despite their disordered structure at the long range. We demonstrated this unique combination of properties in three different catalytic tests. The local order within these ITIs is sufficient to create pore confinement, which not only produces remarkable shape selectivity but also enhances conversion by increasing accessibility. Specifically, the ITIs show a 10-fold increase in activity for Friedel-Crafts alkylation, a 16-fold increase in activity for triisopropylbenzene (TiPBz) cracking, and a two-fold increase in methanol dehydration to dimethyl ether (DME) compared to commercial ferrierite all while maintaining the selectivity of FER. These results highlight the potential of FAU-to-FER ITIs as high-performance catalysts that combine the accessibility of disordered structures with the selectivity typically associated with well-ordered zeolites, opening avenues in zeolite-based catalysis.

Microwave-absorbent materials are typically blended with low-absorption solids to improve local heating efficiency in catalytic systems. However, the mixing method has a crucial effect on the additive's heating efficiency. We report here how by embedding silicon carbide (SiC) nanoparticles in ferrierite (FER) zeolite crystals during their synthesis (FER@SiC), a 2.2-fold increase in the catalytic activity for mesitylene and benzyl alcohol alkylation was achieved compared to a physical mixture of FER and SiC nanoparticles (FER/SiC). While the properties of the zeolite in the FER@SiC hybrid and SiC-free FER zeolites are almost identical, we observed a significant increase in catalytic activity under microwave heating when SiC is present within FER crystals. This enhancement is not mirrored by the physical mixture, highlighting the importance of the SiC addition method and the intimate contact between the additive and catalytic phases for effective microwave heating. Actually, FER@SiC achieves the same conversion with 40% less energy, offering insights into designing more efficient zeolite-based catalysts for sustainable chemistry.

Spent FCC equilibrium catalysts (ECAT) progressively lose activity due to the accumulation of contaminant metals such as Fe and Ni, which block access to active sites and worsen product distribution. In this work, a simple and integrated rejuvenation route is proposed that uses waste poly(vinyl chloride) (PVC) as an in situ HCl source under hydrothermal treatment conditions. During treatment, PVC releases HCl, which promotes partial removal and redistribution of contaminant species while restoring catalyst acidity and accessibility. Two industrial ECAT samples were treated and characterized by XRD, FIB-SEM, AAS, argon physisorption, and NH₃-TPD. The results showed partial removal of metallic contaminants, with Fe being removed more effectively than Ni, preservation of the FAU crystalline structure and particle morphology, and a significant increase in total acidity after treatment. Although some reduction in surface area and mesopore volume was observed, the rejuvenated catalysts exhibited improved performance in cracking triisopropylbenzene and n-hexane, particularly for the bulkier probe molecule, indicating enhanced accessibility to external and near-surface acid sites. To assess practical applicability, the most responsive sample was further evaluated in a pilot-scale Micro Downflow Unit under FCC-relevant conditions. The addition of rejuvenated ECAT to the catalyst inventory produced a conversion response close to that obtained with the addition of fresh FCC catalyst and shifted the product distribution toward lighter fractions at isoconversion. These results demonstrate that PVC-assisted rejuvenation can recover a substantial fraction of ECAT cracking functionality while simultaneously valorizing plastic waste, offering a promising circular route for more sustainable FCC catalyst management.

The coordination chemistry of benzimidazole ligands combines σ donation and π backbonding. Owing to this electronic flexibility, benzimidazole ligands stabilize both electron deficient and electron-rich transition states in the catalytic cycle of Ziegler-Natta polymerizations. In this study, Fe(III) and Ni(II) complexes of 2-substituted-benzimidazoles were tested as catalysts for ethylene and 1-butene oligomerization. The tests realized in toluene yielded mainly butenes and minor amounts of hexenes. When dichloromethane was used as solvent, a tandem reaction took place and 1-butene produced by ethylene dimerization was further oligomerized, yielding octenes and dodecenes as main products. All tested catalysts exhibited moderate selectivity for 1-octene, indicating 1-ω enchainment in 1-butene dimerization. Beyond catalytic tests, a theoretical study of the ligand 2,2′-(furan-2,5-diyl)bis(1H-benzimidazole) confirmed the planar structure of this compound as evidenced by NMR spectroscopy.