| Nitric oxide is the major polluter of the air pollution. People have given much attention on the acid rain and chemical smog which was formed by it. Lean-burn engine has the property of energy saving and enviromental protection, while the traditional three-way catalyst can't remove the nitric oxide effectively under lean-burn conditions. Thus to develop a kind of new catalyst which is suitable for the exhausted gas expelled by the lean-burn engine is becoming popularly in the catalytic field.In this thesis, we focused on the support of HZSM-5 zeolite which had better catalytic activity and treated the zeolite with sulfur acid. Then we loaded Cu by impregnation method. The Cu/HZSM-5 (AT) catalyst was prepared. We added rare earth on the Cu/HZSM-5 (AT) catalyst. The effect of acid treatment and rare earth on catalytic performance was investigated. The influences of preparation was also studied and the structure of catalysts have been investigated by XRD,TG,IR, NH3-TPD, Py-IR,FT-IR and H2-TPR and so on. The results are as follows:(1) Catalysts were prepared by the same method by using different kind of zeolites and different ratio silicon to aluminum zeolites. The results showed that the catalysts made by hydrogen type zeolite had better catalytic performance and the ratio of silicon to aluminum played an important role in catalytic performance.(2) The calcination of HZSM-5 zeolite treated by sulfur acid not only could improve its acid quantity, but also increased strong acid sites with structure of super acid. Results showed that the process of acid treatment increased the conversion of NO and made the catalyst active in wider temperature range.(3) The Cu/HZSM-5(AT) catalyst had high copper loading in this thesis. It showed good stability and better capability of resistance against the water vapour. The addition of rare earth La and Ce on Cu/HZSM-5 (AT) catalyst couldn't improve the catalytic performance.
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