The invention discloses a small
crystal particle Y-shaped
molecular sieve and a preparation method thereof. The property of the small
crystal particle Y-shaped
molecular sieve is as follows: the
molar ratio of Si, O2 / Al2O3 is 10.0-120.0, the
cell parameters are 2.420-2.445 nm, the
crystallization retention is larger than 95 percent, and B acid / L acid is above 7.0. Due to higher
raw material thermal and hydrothermal stability, higher
silicon-aluminum ratio, good stability and uniform framework
silicon-aluminum structure, the small
crystal particle NaY
molecular sieve can ensure the framework continuity of the molecular
sieve, reduce the collapse possibility of the framework structure and maximally keep the integrity of a
silicon-aluminum-
oxygen structure in the modification, namely in the
ammonia exchange,
ammonium fluorosilicate dealumination and silicon reinsertion, hydro-
thermal treatment, aluminum salt and acid mixed water
solution treatment process, thereby having high
crystallization retention. The Y-shaped molecular
sieve can be taken as an
active component of a hydrocracking catalyst, thereby improving the activity of the catalyst, the selectivity of the molecular
sieve and the product quality.