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采用等体积浸渍法制备了CeO2/HBEA催化剂,用于NH3选择性催化还原NO.考察了CeO2负载量、焙烧温度、氧浓度、空速、以及SO2和水蒸气等因素对催化剂活性的影响,并运用BET、X射线衍射(XRD)、扫描电镜(SEM)、热重分析(TGA)、傅里叶红外(FTIR)等手段对该催化剂进行表征,研究了催化剂的晶相、微观形貌与抗毒机制.结果显示:CeO2/HBEA催化剂具有良好的脱硝活性,高活性温度窗口在220～400℃,当反应温度为220℃、空速为12 000 h-1时,NO的转化率达96.49%.H2O的存在对催化剂的脱硝活性无明显影响.SO2一定程度抑制该催化剂的低温脱硝活性,但随着温度的升高,其脱硝活性得到一定恢复.所制备的CeO2/HBEA催化剂有良好的低温活性,能适应较高的空速,且具有较强的抗硫性和抗水中毒性能,有一定的应用前景.
CeO2 / HBEA catalyst was prepared by the same volume impregnation method for the selective catalytic reduction of NO3 by NH3. The effects of CeO2 loading, calcination temperature, oxygen concentration, space velocity, SO2 and water vapor on the catalyst activity were investigated. The catalysts were characterized by means of BET, X-ray diffraction (XRD), scanning electron microscopy (SEM), thermogravimetric analysis (TGA) and Fourier transform infrared spectroscopy (FTIR). The crystal phases, The results showed that CeO2 / HBEA catalyst had good denitrification activity and the high activity temperature window was 220-400 ℃. When the reaction temperature was 220 ℃ and the space velocity was 12 000 h-1, the conversion rate of NO was 96.49% .H2O had no significant effect on the denitrification activity of the catalyst.SO2 inhibited the low temperature denitrification activity of the catalyst to a certain extent, but its denitration activity recovered with the increase of temperature.The CeO2 / HBEA catalyst prepared had good low temperature Activity, can adapt to a higher airspeed, and has strong resistance to sulfur and water poisoning performance, have certain application prospects.