Preparation And Research Of Close Coupled Catalyst

In the thesis the key alumina support material of close coupled catalyst was studied in detail, which was high-temperature-resistant and had high surface area. The relation was systematically investigated among preparation methods, the content of noble metals, the promoter and the catalytic performance of the close coupled catalyst. At last, a close coupled catalyst was successfully prepared with high performance. The single reaction of the close coupled catalyst was studied. The possible mechanism was found for the influence of NO on propane oxidation.In the process of preparation of support, ammonium carbonate was found to be a better precipitant than ammonium hydroxide. The alumina prepared with ammonium carbonate showed higher surface area, larger pore volume, mean pore diameter and higher thermal stability because its precursor was ammonium aluminum carbonate hydroxyl (AACH). The precipitating pH should be controlled on 8.5. When pH was below 8.5, there would produce amorphous hydroxide. But above 8.5, bayerite would be produced. Proper polymer would increase the surface area and mean pore diameter of alumina. La promoter could add the thermal stability of alumina. The content of La should be moderate. Spraying dry method could increase the identity of the alumina pellet. The La-Al2O3 prepared with all controlled condition had a surface area of 167.6 m2/g,...