商用SCR脱硝催化剂碱金属氯化物中毒特性研究  

Poisoning properties of alkali metal chloride to commercial SCR De-NOx catalysts

作　　者：赵霞 李慧[2] 韩健 陆强[2] 崔敏姝 刘丁嘉 庄柯[1] 李文艳[2] ZHAOXia;LI Hui;HAN Jian;LU Qiang;CUI Min-shu;LIU Ding-jia;ZHUANG Ke;LI Wen-yan(State Power Environmental Protection Research Institute,Nanjing 210031,China;National Engineering Laboratory for Biomass Power Generation Equipment,North China Electric Power University,Beijing 102206,China)

机构地区：[1]国电环境保护研究院,江苏南京210031 [2]华北电力大学生物质发电成套设备国家工程实验室,北京102206

出　　处：《应用化工》2018年第S02期15-20,25,共7页Applied Chemical Industry

基　　金：国家973计划(2015CB251501);北京市科技新星(Z171100001117064);国家环境保护大气物理模拟与污染控制重点实验室开放基金课题。

摘　　要：分别制备了V_(2)O_(5)-WO_(3)/TiO_(2)与V_(2)O_(5)-MoO_(3)/TiO_(2)体系的新鲜催化剂,并利用等体积浸渍法与固相扩散法分别进行了碱金属氯化物中毒处理。通过脱硝性能测试,以及程序升温脱附(NH_(3)-TPD)、程序升温还原(H_(2)-TPR)和X射线光电子能谱分析(XPS)等表征,研究了催化剂的碱金属氯化物中毒特性。结果表明:碱金属氯化物对催化剂毒化程度与碱金属的浸渍量、固相扩散时间成正相关;同等K/V摩尔比条件下,固相扩散法的毒害作用比浸渍法更大。碱金属氯化物占据了催化剂表面的活性位点,减少了Br nsted酸性位的数量并降低了酸性强度;提高了H_(2)-TPR的钒物种特征峰温度,降低了催化剂表面的氧化还原性能;同时碱金属氯化物还严重降低了催化剂表面高价钒的比例,从而降低了催化剂的脱硝活性。Fresh V_(2)O_(5)-WO_(3)/TiO_(2) and V_(2)O_(5)-MoO_(3)/TiO_(2) based catalysts were prepared and poisoned by alkali metal chlorides through incipient wetness impregnation and solid phase diffusion methods,respectively.The denitrification activities of these catalysts were tested.And the catalysts were characterized by temperature programmed desorption(NH_(3)-TPD),temperature-programmed reduction(H_(2)-TPR)and X-ray photoelectron spectroscopy(XPS).The results indicated that the poisoning of the catalyst was closely related tOthe alkali metal loading amount and the solid diffusion time.Under the same K/V ratio,the solid phase diffusion is more efficient on catalyst poisoning than incipient wetness impregnation.Alkali metal chlorides would occupy the active sites on the catalyst surface tOdecrease the amount and intensity of Br nsted acid sites,increase the H_(2)-TPR temperature of the characteristic peak of vanadium species,and reduce the redox property of the catalyst surface.Meanwhile,alkali metal chlorides alsOsignificantly decreased the ratiOof V 5+species,and thus,lowering the denitrification activity of the catalysts.

关 键 词：SCR催化剂 中毒 碱金属氯化物 等体积浸渍 固相扩散 

分 类 号：X511[环境科学与工程—环境工程]