Aluminum-based composite particles are widely applied complex catalyst materials in oil refining. Due to their tunable shape, porosity, and acidity, they are commonly used for the production of cracking catalysts. Shaping of well-defined particles remains a challenge for industrial catalyst preparation by spray drying, because catalyst properties must satisfy local demands of a refinery. The selectivity can be modified and the cracking activity enhanced with acid binders, e.g., AlCl₃. Therefore, peptization of AlCl₃-containing suspensions with zeolite Y and kaolin was characterized by pH value, ²⁷Al NMR spectroscopy, and zeta potential. A new control strategy for binding of kaolin and zeolite Y in spray drying was developed by adjusting the pH and binder Al/Cl ratio.