活性炭的预处理对CeO2/AC催化剂NH3选择性催化还原NOx性能的影响  

The effect of the oxidation method of an activated carbon on the selective catalytic reduction of NO_x with NH_3 over CeO_2/activated carbon catalysts

作　　者：黄利华[1] 李雪[1] 陈耀强[2] HUANG Li-hua 1 , LI Xue 1 , CHEN Yao-qiang 2(1. Institute of Environment and Resource of Southwest University of Science and Technology, Mianyang 621010, China;2. College of Chemistry of Sichuan University, Chengdu 610064, Chin)

机构地区：[1]西南科技大学环境与资源学院,四川绵阳621010 [2]四川大学化学学院,四川成都610064

出　　处：《新型炭材料》2018年第3期237-244,共8页New Carbon Materials

摘　　要：为了改善活性炭(AC)负载的CeO_2基催化剂的脱硝性能,采用空气热氧化或硝酸对活性炭进行预处理,考察了预处理方式对其负载的CeO_2基催化剂氨选择性催化还原(NH_3-SCR)NO_x反应性能的影响。对预处理后的活性炭及其负载的CeO_2基催化剂进行了红外光谱(FTIR)、NH_3程序升温脱附(NH_3-TPD)、N_2吸附-脱附、X射线衍射(XRD)及H_2-TPR等表征。结果表明:硝酸预处理显著增加了活性炭表面含氧官能团、增强了表面酸性,提高了其负载的CeO_2基催化剂的氧化还原性能,促进了催化剂表面NH_3的吸附和活化,使催化剂表现催化优异的NH_3-SCR脱硝性能。该催化剂对NO_x的起燃温度和完全转化温度分别为75℃和190℃,显著优于空气热氧化处理的活性炭制备的催化剂,但H_2O易导致催化剂活性下降。An activated carbon （AC） was oxidized with air at 300 ℃ for 4 h or with 30 wt% HNO 3 at 60 ℃ for 4 h under reflux before it was loaded with CeO 2 by an impregnation method to prepare CeO 2/AC catalysts for the selective catalytic reduction of NO x in flue gas with NH 3. The influence of the oxidation method on the performance of the catalysts was investigated. Both catalysts were characterized by FTIR, N 2 adsorption, XRD, temperature-programmed desorption of NH 3 and temperature-programmed reduction with H 2. Results showed that the HNO 3 oxidation increased both the number of oxygen functional groups and the surface acidity of the AC and the redox activity of the CeO 2/AC-HNO 3, which favored the adsorption and activation of NH 3 with the CeO 2/AC-HNO 3 and hence its catalytic performance. The onset and full conversion temperatures of NO x over the CeO 2/AC-HNO 3 catalyst were 75 and 190 ℃, respectively, which were significantly lower than those over the CeO 2/AC-air catalyst. However, the activity of the CeO 2/AC-HNO 3 catalyst was easily inhibited by H 2O.

关 键 词：活性炭 预处理 CEO2 NH3选择性催化还原 NOx 

分 类 号：O643.36[理学—物理化学]