The study of isoamylene oligomerization over a number of microporous zeolites such as H–Y, H–MOR, H–Beta, H–ZSM-12, and H–ZSM-5 revealed that the isoamylene conversion rate decreases in the following order: H–MOR > H–Y > H–Beta-40 >> H–ZSM-12 > H–ZSM-5. The maximum yields of isoamylene oligomers were achieved by using H–MOR (85.0%), H–Y (80.1%), and H–Beta-40 (79.8%). The predominant isoamylene oligomers are dimers regardless of the zeolite catalyst used. The trimer yield reaches its highest when wide-pore zeolites like H–MOR, H–Y, or H–Beta-40 are employed. An increase in the number of acid sites enhances monomer conversion rate, oligomer yield, and oligomer molecular weight. Conditions for producing isopentene dimers and trimers with the maximum possible yield were determined.

New opportunities to control the morphology and size of SAPO-11 molecular sieve crystals through the preliminary formation of intermediate phases.

The formation of silicoaluminophosphate gels using boehmite, Al isopropoxide, and di-n-propylamine as a template of silicoaluminophosphate gels as well as their subsequent crystallization into SAPO-11 molecular sieves was studied in detail using X-ray fluorescence spectroscopy (XRF), powder X-ray diffraction (XRD), Raman spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM), and N2 adsorption–desorption methods. The effect of the chemical and phase composition of silicoaluminophosphate gels on the physicochemical properties of SAPO-11 molecular sieves was shown. The secondary structural units that the AEL lattice is composed of were found to be formed at the initial stage of preparation involving aluminum isopropoxide. Several approaches to control their morphology and secondary porous structure are also proposed.

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