The present invention discloses a modified Y type
molecular sieve, which is characterized in that the
molecular sieve is modified by using
rare earth, iron,
copper and
phosphorus, wherein
rare earth content in the
molecular sieve is 8-23 wt% (calculated as
rare earth oxide),
iron content in the molecular
sieve is 0.1-3.0 wt% (calculated as Fe2O3),
copper content in the molecular
sieve is 0-3.0 wt% (calculated as CuO),
phosphorus content in the molecular
sieve is 0-2.0 wt% (calculated as P2O5), and
sodium oxide content in the molecular sieve is 0.1-2.5 wt%. According to the modified Y type molecular sieve, a molecular sieve acid amount measured by <31>P MAS NMR after absorbing tri-n-butylphosphine
oxide is 1.400-4.500 mmol.g<-1>, and a molecular sieve acid amount measured by <31>P MAS NMR after absorbing trimethyl
phosphine oxide (TMPO) is 2.300-6.600 mmol.g<-1>. The molecular sieve has a high acid amount, especially a high outer surface acid amount, and can be adopted as an
active component to effectively
resist harm effects on the molecular sieve acid center by the basic
nitrogen macromolecules so as to provide an excellent anti-basic
nitrogen performance.