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One dimensional pore zeolites such as ZSM-22 (TON) are potential catalysts for hydrocarbon conversion reactions, including methanol-to-propylene (MTP) reaction. Different crystal lengths of ZSM-22 zeolite were prepared and examined for the MTP reaction. Nanosized TON zeolites with crystal length of ∼100 nm were synthesized by dynamic hydrothermal synthesis. The zeolite crystal length was tuned by using ethylene glycol as crystal growth modifier. The crystal lengths of ZSM-22 zeolites (approximately 100 and 300 nm) were confirmed from FE-SEM and TEM micrographs. However, the textural properties such as BET surface area and crystallinity of crystals were fairly similar. The effect of ZSM-22 crystal length on catalytic activity and propylene yields in the methanol-to-propylene reaction was investigated. The TON nanocrystals resulted in a higher propylene yield and better catalytic stability compared to the submicrometer zeolite (∼300 nm). Deactivation was observed for all catalysts. However, longer lifetime was observed for the nanosized ZSM-22 with crystal length of ∼100 nm.

Steam catalytic cracking was performed over metal modified BEA zeolite. Nickel and cobalt were introduced to the desilicated BEA zeolite by substitution treatment. The method of metal incorporation used here allowed incorporation of the metal(s) into the framework matrix of BEA in tetrahedral form together with the external surface. The successful incorporation of nickel/cobalt into the BEA framework in tetrahedral form was confirmed from FTIR spectra and UV–vis. The quantity of metals attached to BEA zeolite was calculated by EDX. The changes and defects of the BEA structure were studied from XRD patterns and SEM micrographs. The metal incorporation significantly increased the total acidity, as confirmed by NH3-TPD and pyridine FTIR analysis. The attachment of metals considerably increased the conversion of n-dodecane as compared to the parent sample. The stability of BEA zeolite was also enhanced significantly. However, the addition of Co to Ni incorporated BEA zeolite had a negative effect on both n-dodecane conversion and BEA stability.

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Hierarchical ZSM-48, a one-dimensional pore system zeolite with the presence of mesopores, was obtained by post-synthesis alkaline and acid treatments. Hierarchical ZSM-48 exhibited excellent hexane cracking activity compared to parent ZSM-48, which can be attributed to better diffusion as a result of the created mesoporosity. Moreover, the post-synthesis treatment allowed for manipulation of the distribution of active sites. Consequently, better stability and higher propylene selectivity were accomplished. The spent catalyst was regenerated by removing the deposited coke from the pores, and the regenerated catalyst was characterized again to investigate the recyclability of the hierarchical structure achieved. Parent ZSM-48 showed the same textural and acidic properties after regeneration, while the structure of the post-treated sample suffered from serious defects. The defects severely decreased the number of active sites as measured by pyridine Fourier transform infrared spectroscopy and caused major structural collapse as observed by scanning electron microscopy and transmission electron microscopy. 65 preparing hierarchical zeolites, especially because the structure 66 of these hierarchical zeolites is suffering from serious defects. 67 The durability and preservation of zeolite properties are highly 68 required for the catalyst, which will be used in FCC or any 69 process because the calculations of material balance of 70 separation units will be based on product selectivity.