基于ZrO_2/TiO_2催化H_2O_2氧化低温脱硝的实验研究  

Experimental study on low temperature H_2O_2 oxidative denitrification over ZrO_2/TiO_2 catalyst

作　　者：周锦晖[1] 王琦[2] 刘丁嘉 崔敏姝 陆强[2] 庄柯[1] 杨勇平[2] ZHOU Jinhui;WANG Qi;LIU Dingjia;CUI Minshu;LU Qiang;ZHUANG Ke;YANG Yongping(State Power Environmental Protection Research Institute, Nanjing 210031;National Engineering Laboratory for Biomass Power Generation Equipment, North China Electric Power University, Beijing 102206)

机构地区：[1]国电环境保护研究院,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：《环境科学学报》2019年第2期601-609,共9页Acta Scientiae Circumstantiae

基　　金：国家重点基础研究发展计划"973"计划(No.2015CB251501);北京市科技新星计划(No.Z171100001117064);霍英东教育基金会项目(No.161051)

摘　　要：以纳米TiO_2为载体,采用等体积浸渍法掺杂过渡金属氧化物ZrO_2进行改性,制备了一系列ZrO_2/TiO_2催化剂,以催化H_2O_2低温氧化NO脱硝,并采用X射线衍射(XRD)、H_2程序升温还原(H_2-TPR)、O_2程序升温氧化(O_2-TPO)、X射线光电子能谱(XPS)及电子顺磁共振(EPR)等表征分析探究了影响H_2O_2脱硝活性的因素.表征结果表明ZrO_2的负载量会影响催化剂中晶格氧的含量,晶格氧相对含量的增加有利于氧化还原反应中的电子传递,这是促进H_2O_2活化分解的关键.在微观表征的基础上,通过实验研究筛选获得了催化剂的最佳ZrO_2负载量,同时对比考察了非催化和纳米TiO_2催化作用下的H_2O_2氧化低温脱硝性能;针对获取的最优催化剂,进一步考察了不同烟气工况对催化剂活性的影响.实验结果表明,ZrO_2/TiO_2催化剂能有效促进H_2O_2的活化分解实现低温脱硝,且ZrO_2负载量为4%(质量分数)时,催化活性最高;在烟温为160℃、[H_2O_2]/[NO]物质的量比为2及空速为30000 h^(-1)时,NO转化率最高可达81%.A series of ZrO2/TiO2 catalysts were prepared by incipient wetness impregnation method to catalyze the low-temperature oxidation denitrification by H2O2. The characterization analyses of X-ray diffraction(XRD), H2-temperature programmed reduction(H2-TPR), O2-temperature programmed oxidation(O2-TPO), X-ray photoelectron spectroscopy(XPS) and electron paramagnetic resonance(EPR) were performed to explore the factors affecting the denitrification activity of H2O2. The characterization results showed ZrO2 loading will affect the content of the lattice oxygen in the catalyst. The increase of lattice oxygen relative content is beneficial to the electron transfer during redox reaction, which is the key to promote the decomposition of H2O2. The optimum ZrO2 loading of the catalyst was obtained by experimental research. And the performance of ZrO2/TiO2 catalyzed H2O2 oxidative denitrification was compared with that of non-catalytic and nano-TiO2. The effect of flue gas conditions on the catalyst activity was further investigated. The results showed that ZrO2/TiO2 catalyst could effectively promote the decomposition of H2O2 to realize low temperature denitrification. The best catalytic performance was obtained at ZrO2 loading of 4%. Under the flue gas temperature of 160 ℃,[H2O2]/[NO] molar ratio of 2 and space velocity of 30000 h^-1, the NO conversion reached as high as 81%.

关 键 词：H2O2 NO氧化 ZrO2/TiO2 低温脱硝 

分 类 号：X701[环境科学与工程—环境工程]