Immobilization of active components on support materials is an effective strategy to minimize the negative environmental and health impacts of hazardous Lewis acid catalysts. In this study, we synthesized immobilized Al–Ti bimetallic catalysts supported on MgO–Al2O3–SiO2 ternary oxide (Al–Ti/MAS) with accurately controlled compositions and pore structures. We also characterized supports and catalysts using various techniques. Further, we examined their catalytic activity and stability using a fixed-bed reactor. Compared with γ-Al2O3-derived catalyst, the Al–Ti/MAS catalysts feature more Lewis acid sites and better pore structure accessibility, which lead to much higher activity and stability. Among these MAS samples, M-3 (Si/Al molar ratio = 9.76) presents the highest loading of active species with a chlorine content of 16.7%, leading to the highest PAO yield of 94.6% and the best stability. In addition, the deactivation of the MAS-derived Al–Ti bimetallic catalysts is mainly ascribed to the loss of activ...