Preparation method of Mo modified Cu-SSZ-13 catalyst

The invention discloses a preparation method of a Mo modified Cu-SSZ-13 catalyst. Ammonium molybdate tetrahydrate and copper nitrate are taken as precursors and are directly dipped and loaded to an H-SSZ-13 (SiO2:Al2O3=10:1) molecular sieve. In the Mo modified Cu-SSZ-13 catalyst, the mass percent of Cu is 4 percent, and the mass percent of Mo is 0.2 to 3 percent. Active components are transition metal Cu , a Bronsted acidic locus and a Lewis acidic locus. The transition metal catalyzes the NO oxidation, and all the acidic loci take charge of ammonia activation. When the addition of Mo is 0.2 percent, a NO conversion rate temperature window is widened; when the addition of Mo is 0.5 percent or more, a NOx conversion rate temperature window is reduced. Through the adoption of the Mo modified Cu-SSZ-13 catalyst, the discharge of NOx can be reduced, and meanwhile the generation of a by-product N2O can be reduced.