Mn-Ce/TiO_2低温选择性催化还原催化剂二氧化硫中毒及再生特性  

Research on characteristics of SO_2-poison and regeneration of Mn-Ce/TiO_2 catalyst for low temperature selective catalytic reduction

作　　者：胡宇峰[1] 薛建明[1] 王小明[1] 盛重义[2] 廖伟平[2] 

机构地区：[1]国电环境保护研究院,江苏南京210031 [2]南京师范大学,江苏南京210042

出　　处：《工业催化》2013年第4期27-33,共7页Industrial Catalysis

基　　金：国家高技术研究发展计划(863计划)(SS2013AA062001)资助项目

摘　　要：采用液相共沉淀法制备Mn-Ce/TiO2低温选择性催化还原催化剂,催化剂在120℃无二氧化硫条件下低温SCR活性高,NO转化率为92%。利用BET、SEM、TEM、XRD和XPS等技术对催化剂的二氧化硫中毒特性进行分析,结果表明,催化剂中毒是由于(NH4)2SO3和(NH4)2SO4在催化剂表面发生沉积,采用水洗、加热和还原气体保护加热等方式对催化剂进行再生实验,发现水洗对催化剂活性再生非常有效,特别是在水洗浸泡过程中采用超声波震荡。用离子色谱技术对水洗副产物进行分析,发现水洗液中主要离子为NO3-、SO24-和NH4+。Mn-Ce/TiO2 catalyst prepared by a novel co-precipitation method was studied. The results showed that Mn-Ce/TiO2 catalyst exhibited high SCR activity at low temperature and NO conversion of 92% was attained under the condition of reaction temperature 120 ℃ without the existence of SO2 in the flue gas. The SO2-poisoned Mn-Ce/TiO2 catalysts were characterized by BET, SEM, TEM, XRD and XPS. The mechanism of SOE-poison was mainly related to the deposition of （ NH4 ） 2 SO3 and （ NH4 ） 2 SO4 on the surface of the catalysts. The methods of water washing, thermal regeneration and regeneration by reduetive gas protection were used to regenerate Mn-Ce/TiO2 catalyst, and water washing method showed good regeneration effect for the deactivated catalysts, especially with ultrasonic vibration. The compositions of liquid phase attained by water washing was analyzed by ion chromatography. It was found that the main ions in the water washing liquid were NO^- ~SO^- and NH~＋.

关 键 词：催化剂工程 低温SCR Mn-Ce TIO2催化剂 二氧化硫中毒 水洗再生 

分 类 号：TQ426.6[化学工程] O643.36[理学—物理化学]