Abstract: TiO2-SiO2 mixed oxides (TS) were prepared under different pH values by co-precipitation method and characterized by means of N2-physisortion，X-ray diffraction，temperature-programmed desorption and infrared spectroscopy. With these TS oxides as carrier and CuO, Cr2O3 and CeO2 as the active components, Cu-Cr-Ce/TS catalysts were prepared and their catalytic performance for the selective reduction of NO by NH3 was investigated between 140 ℃and 220 ℃. Results showed the Cu-Cr-Ce/TS catalyst，in which the TS was prepared under pH values between 10 and 11，appears to have the highest catalytic activity under lower temperature. This is due to the larger specific surface area and the more weak acid center of the TS support，through which a large number of NH3 molecules can be adsorbed as to react easily with NO.

摘要： 采用共沉淀法，在不同pH值下制备了3种TiO2-SiO2（TS）复合氧化物，采用BET、XRD、NH3-TPD和FTIR等方法对样品进行了表征；并以3种TS为载体，负载CuO、Cr2O3和CeO2活性组分，考察了不同Cu-Cr-Ce/TS催化剂在140～220 ℃NH3选择性催化还原NO的性能。结果表明，以pH值10～11的TS载体制备的Cu-Cr-Ce/TS催化剂具有最优的低温活性，这是由于该载体具有较大的比表面积和更多弱酸中心，能吸附大量易于与NO反应的氨。