Five Cu-ZSM-5 catalysts were obtained by treating Na-ZSM-5 (Si/Al ratio=15) with aqueous solutions of different Cu precursors (CuCl

2

Cu(NO

3

)

2

CuSO

4

Cu(CH

3

COO)

2

and ammoniacal copper (Ⅱ) complex ion). After being pretreated in flowing He at 500℃ to form active Cu

+

these catalysts exhibited quite different activities in catalytic decomposition of N

2

O. CZM-AC(Ⅱ) (prepared by ammoniacal copper (Ⅱ) complex ion) with 9.4 wt% Cu content was the most active among these Cu-ZSM-5 catalysts

achieving almost complete N

2

O conversion at 400℃. CZM-CA (prepared using Cu(CH

3

COO)

2

as the Cu precursor) with 2.8 wt% Cu content was the second most active catalyst among these Cu-ZSM-5 catalysts

achieving almost complete N

2

O conversion at 425℃. CZM-CC

CZMCN

and CZM-CS prepared by using CuCl

2

Cu(NO

3

)

2

or CuSO

4

as the Cu precursor with similar Cu contents (≈1.7 wt%) were the least active among these Cu-ZSM-5 catalysts

achieving ca. 90% N

2

O conversion at 500℃. XRD

ICP

SEM

TEM

EDX-mappi

ng

and CO-IR experiments were conducted to characterize relevant samples. The superior activity of CZM-AC(Ⅱ) can be attributed to the high contents of total Cu

+

and dimeric Cu

+

among these samples. The influence of co-fed O

2

or H

2

O on the catalytic performance of typical samples was also studied.