Abstract In-situ zeolites NaY and Na[B]Y were synthesized on microspherical matrices of kaolin to obtain FCC catalysts. An alkaline pretreatment of the matrix was investigated in order to evaluate its effect on matrix properties and crystallization of the in-situ synthetized zeolites. Catalysts were characterized by SEM, TEM, Ar adsorption, XRD and NH 3 -TPD. It was observed an increase in the surface area and mesoporosity of the alkaline treated catalysts either synthetized with the presence of boron or with no boron in the hydrothermal reaction mixture. Ammonia TPD analyses have shown an increase in the amount and strength of the acidity of the catalysis with the zeolites crystallized on the pretreated matrices and exchanged with lanthanum ions. Thus, a combination between higher concentration of stronger acid sites and higher proportion of mesoporous generated in the matrices treated with alkaline solution had resulted in more active catalyst as shown by the triisopropylbenzene cracking experiments conducted here. Graphical abstract