A series of CoZSM-11 catalysts were prepared by different methods and tested in N2O decomposition. The N2O conversion and specific rate of CoZSM-11 prepared by wet DDD107498 exchange increase with the decrease in Si/Al ratio. The activity can be further enhanced when synthesizing the catalyst by buffered ion exchange or semi-continuous ion exchange, whereas the catalyst prepared by impregnation shows the lowest activity. H2-TPR, XPS and UV–vis DRS characterizations indicate that Co2+ ions are the main active sites for N2O decomposition. The sequence of activity is a consequence of the increased amount of active Co2+ species as well as the weakened Co2+O bond. Moreover, the α-type Co2+ ions coordinated to framework oxygen atoms are indicated to the most active sites. CoZSM-11 is mitosis found to be more active and stable than CoZSM-5 for N2O decomposition.
AcknowledgmentsW. Hua and Y. Yue thank the financial support by the National Natural Science Foundation of China (20773027 and 21273043) and the Science and Technology Commission of Shanghai Municipality (13DZ2275200). Z. Ma thanks the financial support by the National Natural Science Foundation of China (21477022). Y. Luo thanks the financial support by National Fund for Talent Training in Basic Science (J1103304).