MnO_x/PG低温SCR催化剂二氧化硫中毒及再生特性  

Sulfur dioxide poisoning and regeneration characteristics of MnO_x/PG low temperature SCR catalysts

作　　者：张先龙 马康 蔡程 吴雪平 王钧伟[2] 肖客松 ZHANG Xianlong;MA Kang;CAI Cheng;WU Xueping;WANG Junwei;XIAO Kesong(School of Chemistry and Chemical Engineering Hefei University of Technology,Hefei,230009,China;School of Chemistry and Chemical Engineering Anqing Teachers College,Anqing,246000,China;Instrumental Analysis Center Hefei University of Technology,Hefei,230009,China)

机构地区：[1]合肥工业大学化学与化工学院,合肥230009 [2]安庆师范学院化学与化工学院,安庆246000 [3]合肥工业大学仪器分析中心,合肥230009

出　　处：《环境化学》2019年第6期1403-1412,共10页Environmental Chemistry

基　　金：国家自然科学基金(40902020,51002042);高等学校博士学科点专项科研新教师基金(120090111120019);中央高校基本科研业务费专项基金(2011HGQLI003)资助~~

摘　　要：采用等体积浸渍法制备了锰氧化物负载凹凸棒石(MnOx/PG)低温SCR(Selective Catalytic Reduction)催化剂,在含硫气氛中进行低温SCR催化脱硝反应后受SO2的毒化作用而失活.考察了热处理和水洗两种再生方式及再生工艺条件对中毒后的MnOx/PG催化剂活性恢复的影响.结果表明,热处理不能有效恢复催化剂活性,而水洗再生可以使中毒催化剂的活性完全恢复;两种再生方法的工艺条件均对催化剂活性恢复效果不大.通过BET、SEM、元素分析等表征手段对催化剂中毒机理和中毒前后性能变化进行分析.结果表明,硫酸铵盐和多聚SO4^2-的形成是导致MnOx/PG催化剂活性降低的主要原因.热处理使催化剂部分活性恢复的原因在于表面硫酸铵盐的分解,而水洗再生可以有效的去除催化剂表面的硫酸铵盐和SO4^2-聚合体,进而催化剂活性完全恢复.Manganese oxide supported palygorskite(MnOx/PG) as low temperature SCR catalyst was prepared by means of equal volume impregnation.After being used for lower temperature SCR in SO2 contained gases,catalysts were found to be deactivated drastically.Regeneration of the poisoned MnOx/PG catalyst was carried out by heat-treatment and water-washing,respectively.It was found that the heat-treatment partly restoreed poisoned catalyst activity,and the water regeneration completely restore the activity of the poisoning catalyst.Heat-treatment regeneration and water-washing regeneration had no obvious effect on regeneration results under different conditions.Poisoned mechanism of catalyst and performance changes were analyzed by BET,SEM,elemental analysis and other characterizations.The results show that the formation of ammonium sulfate salt and SO4^2- polymer were the main reason for the decrease of MnOx/PG catalyst activity.Further studies have shown that heat-treatment regeneration restores partly activity of the catalyst due to the decomposition of the surface ammonium sulfate salt.However,the water-washing regeneration can effectively remove the ammonium sulfate salt as well as the polymerized SO4^2- species,resulting in complete recovery of the catalyst activity.

关 键 词：低温SCR MnOx/PG催化剂 二氧化硫中毒 水洗再生 

分 类 号：X701[环境科学与工程—环境工程]