With the significant increase of automobile quantity, the pollution caused by automobile exhaust has become more and more severe, especially for the NOx, it not only will result in the formation of photochemistry smoke, acid rain and the human body breath endanger, but also will destroy the ecological environment, as well as bring the serious influence on the mankind's life and production. The traditional three-way catalyst would be ineffective under lean-burn condition, therefore, researching a new type of catalyst for automobile exhaust purification becomes the current topic that many scholars pay much attention to.Two kinds of catalysts have been studied in this thesis: one is Cu/La/SO42-/Al2O3 catalyst that has high catalytic activity and thermal stability, which was prepared by modified γ -Al2O3 carrier with SO42- followed by addition of La and loading with Cu2+ afterward; The other is Cu/SO42-/La2O3-ZrO2-Al2O3 catalyst that prepared bymodified La2O3ZrO2-Al2O3 composite support with SO42- followed by loading with Cu2+. Meanwhile, the structure and property of catalysts have been investigated by using the catalysts performances and the results of characterization. The results are showed as follows:1 .The SO42- modification can facilitate an increase of the acidity on the surface of the catalyst, and improve the catalytic activity of catalysts effectively. Meanwhile, the addition of La promoter could greatly increase the thermal stability and reducibility of the catalyst, and could restrain the formation of CuAl2O4 sharp stone availably, thus expand the operation temperature window clearly.2. The property of La2O3-ZrO2-Al2O3 composite support made by hydrothermal synthesis was better than the singleness carriers. The addition of ZrC>2 contributed mainly to the increase of the catalytic activity in low temperature of the title catalysts, whilst the addition of La2O3 contributed mainly to the enhancement of the thermal stability of the catalyst.3. After the SO42- modification, the SO42- was able to combine with Zr to form a chelate bidentate state which could largely facilitate an increase of the acid quantity... |