Department of Environmental Engineering, Beijing University of Chemical Technology, Beijing, 100029 China.
Environ Technol. 2011 May-Jun;32(7-8):891-900. doi: 10.1080/09593330.2010.517219.
The catalyst CuSO4-CeO2/TiO2-SiO2 (CuSO4-CeO2/TS), for low temperature catalytic reduction (LT-SCR) of NO with NH was prepared by the impregnation method. The impacts of H2O and SO2 on the catalyst were investigated. Experiments showed that H2O brought down the catalyst's activity at low reaction temperature. However, this negative effect of H2O could be mostly eliminated with a raised temperature of above 220 degrees C. In a 10-hour experiment on the catalyst's resistibility to SO2 poisoning, NO conversion increased slightly by the promoting effect of SO2. The same catalyst underwent continuous examination with both SO2 and H2O in the feed gas; NO conversion of around 90.2% was maintained for 37 hours, showing better performance than CuSO4-CeO2/TiO2. This suggested that SiO2 in the TiO2-SiO2 catalyst supported the supression of the oxidization of SO2 to SO3. Therefore, the formation of ammonium sulphate over the catalyst and the sulphation of CeO2 in the catalyst were greatly alleviated, leading to a better resistibility of the catalyst to SO2 poisioning. After the 37 hours, the catalyst activity began to fall, and an irrecoverable deactivation of the catalyst was observed.
采用浸渍法制备了用于低温 SCR 脱硝的催化剂 CuSO4-CeO2/TiO2-SiO2（CuSO4-CeO2/TS）。考察了 H2O 和 SO2 对催化剂的影响。实验表明，H2O 在低温下降低了催化剂的活性。然而，当反应温度高于 220℃时，H2O 的负面影响可基本消除。在 SO2 中毒的 10 小时实验中，SO2 的促进作用使 NO 转化率略有增加。在含有 SO2 和 H2O 的进料气中，相同的催化剂进行了连续测试；NO 转化率维持在 90.2%左右 37 小时，性能优于 CuSO4-CeO2/TiO2。这表明 TiO2-SiO2 催化剂中的 SiO2 抑制了 SO2 向 SO3 的氧化。因此，催化剂上的硫酸铵形成和催化剂中 CeO2 的硫酸盐化得到了极大缓解，从而提高了催化剂对 SO2 中毒的抗性。37 小时后，催化剂活性开始下降，观察到催化剂不可恢复的失活。
