With increasingly stringent environmental regulations on gasoline composition

the replacement of hazardous liquid acid catalysts [hydrogen fluoride (HF) and H2SO4] with solid acid alternatives for isobutane–butene alkylation has become imperative. Zeolite Y-based catalysts offer promising eco-friendly alternatives; however

their commercial application remains limited by rapid deactivation caused by insufficient Brønsted acid site (BAS) density and unfavorable oligomerization side reactions. Herein

we report a mechanism-guided pre-mix synthesis strategy that eliminates one high-temperature calcination step and maximizes zeolite–binder interactions to substantially enhance catalyst acidity and stability. The designed NH4Y–Al2O3 catalyst exhibits a total BAS density that is 1.9 times higher and a strong BAS density that is 2.6 times higher than conventionally prepared HY–Al2O3. Comprehensive characterization by X-ray diffraction

magic-angle spinning nuclear magnetic resonance (3Q

27Al

and 29Si)

temperature-programmed desorption of NH3

and pyridine adsorption infrared spectroscopy reveals that the enhanced acidity originates from: (i) enhanced framework Al retention and local structural stability due to reduced thermal dealumination

evidenced by increased unit cell parameter from 2.448 to 2.459 nm; and (ii) migration of Al species from the Al2O3 binder to ion-exchange positions and framework sites

forming distorted tetrahedral Al species. The pre-mix method reduces zeolite agglomeration

increases interfacial contact area

and lowers energy consumption. In isobutane–butene alkylation

NH4Y–Al2O3 demonstrates exceptional catalytic performance: deactivation time is extended by 70% (48 h vs. 28 h)

C8 selectivity increases by 7 percentage points

and alkylate yield reaches 94.35%

surpassing conventional H2SO4 (93.10%) and HF (91.50%) systems. The hydrogen transfer rate doubles that compared to conventional catalysts

effectively suppressing oligomerization and coke formation. These findings establish design principles for zeolite-based alkylation catalysts and demonstrate an energy-efficient synthesis route that reduces carbon emissions and offers potential for industrial scale-up.