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研究报告

周锦晖,王琦,刘丁嘉,崔敏姝,陆强,庄柯,杨勇平.基于ZrO₂/TiO₂催化H₂O₂氧化低温脱硝的实验研究[J].环境科学学报,2019,39(2):601-609

Experimental study on low temperature H₂O₂ oxidative denitrification over ZrO₂/TiO₂ catalyst

基金项目：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TiO₂为载体，采用等体积浸渍法掺杂过渡金属氧化物ZrO₂进行改性，制备了一系列ZrO₂/TiO₂催化剂，以催化H₂O₂低温氧化NO脱硝，并采用X射线衍射（XRD）、H₂程序升温还原（H₂-TPR）、O₂程序升温氧化（O₂-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H₂O₂脱硝活性的因素.表征结果表明ZrO₂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H₂O₂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ZrO₂负载量，同时对比考察了非催化和纳米TiO₂催化作用下的H₂O₂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，ZrO₂/TiO₂催化剂能有效促进H₂O₂的活化分解实现低温脱硝，且ZrO₂负载量为4%（质量分数）时，催化活性最高；在烟温为160℃、[H₂O₂]/[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%.

Abstract：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%.