铁基中低温SCR脱硝催化剂性能研究.
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对非负载型Fe2O3催化剂研究表明：模板法比共沉淀制备的催化剂具有更大的比表面积，更强的氧化性和酸性，促进了催化剂脱硝活性的升高；前者比后者的活性温区宽，并且具有较好的高温脱硝活性。对不同含量CeO2催化剂的表征比较发现，当CeO2含量为2 %和4%时具有相对较高的催化活性和相对较小的氨气氧化率，这主要是由催化剂中铁物种氧化性的变化导致的。
对多元金属氧化物基本性质的研究表明，多元金属氧化物中主要有Fe、Si、Al等多种元素，颗粒表面存在Si、Na、Al、V等元素的富集。多元金属氧化物比表面积极低，基础脱硝活性较低，不适合直接作为脱硝催化剂或者活性组分。
制备了XO为催化剂基体，TiO2为载体，Fe2O3为活性组分的催化剂，考察基体对催化剂的影响。实验结果表明，加入多元金属氧化物后，催化剂比表面积减小、氧化性增强。在250℃-350℃内催化剂的脱硝活性在90 %以上，但是活性温窗较窄。分别使用CeO2、MoO3、WO3对催化剂进行掺杂，实验结果表明：掺杂后催化剂比表面积增大，有利于氨气的吸附，促进SCR反应的进行；CeO2掺杂后催化剂的脱硝活性在整体上提高，但是最佳活性温窗没有变宽或者变化；MoO3、WO3掺杂后催化剂的中低温活性降低，高温活性Fra Baidu bibliotek高，活性温窗宽，并向高温移动。
First, a series of experiments were conducted to research denitration catalyst based on Fe, including the preparation method and the content of CeO2. The catalysts were characterized with XRD, XPS, H2-TPR, BET and UV-Vis DRS, and the denitration activity and the oxidation rate of NH3over catalysts was evaluated. Then, the basic properties of multiple metal oxide were characterized by the means of XRD, XPS, XRF, BET, and the basic denitration activity of multiple metal oxide was studied. Non supported catalysts was prepared with XO, TiO2, Fe2O3as base material, carrier and active constituent respectively. The effects of XO and different assistant on the SCR catalytic activity was investigated.
本文首先考察了制备方法、助剂CeO2含量两个因素对非负载型Fe2O3催化剂性能的影响。通过XRD、XPS、H2-TPR、BET比表面积测试、UV-vis DRS等表征手段，对催化剂进行了表征，并且对催化剂的脱硝活性和对氨气的氧化率进行评价。然后，通过XRD、XPS、XRF、BET比表面积测试的表征手段，分析了一种工业级多元金属氧化物(MO)的基本性质，研究了其基础脱硝活性。以XO为催化剂基体，TiO2为载体，Fe2O3为活性组分制备了负载型脱硝催化剂。考察了XO及不同助剂对SCR催化活性的影响。利用XRD、H2-TPR、BET比表面积测试等技术对制备的催化剂进行了表征。
At present, there exist some problems in the commercial catalyst, the price is expensive, narrow active temperature window, and abandoned catalyst will lead to secondary pollution. So, it has very important significance to develop environmental friendly catalyst, low temperature, high efficiency and cheap. Iron oxide, has received the attention of scholars both at home and abroad, because it has advantages of environmentally friendly, low prices,and strong reducibility.This paper focuses on the preparation and characterization of denitration catalystbased on Fe.
铁基中低温SCR脱硝催化剂性能研究
摘
氮氧化物(NOx)对人体、环境的危害很大，是目前国内外急需解决的问题之一。选择性催化还原法具有脱硝效率高、N2选择性好等优点，得到广泛使用。商业化的脱硝催化剂存在价格昂贵，活性温窗窄，活性窗口温度较高且废弃的催化剂易造成二次污染等问题，所以，开发廉价、低温、高效的环境友好型催化剂具有十分重要的意义。铁的氧化物具有环境友好、价格低廉以及还原性强等优点，在NOx选择催化还原(SCR)脱除领域已经受到了国内外学者的广泛关注。本文主要针对氧化铁脱硝催化剂的制备、表征等各方面进行了研究。
关键词：选择性催化还原，多元金属氧化物，氧化铁，脱硝
ABSTRACT
In recent years, with the rapid development of industrialization in China, atmospheric pollution caused by the burning of fossil fuels has being more and more serious. NOx is one of the main atmospheric pollutants, which bring huge harm to human body and environment, it is one of the urgent problems at home and abroad to be solved. There are many methods controlling NOx emission，one of the most widely used is selective catalytic reduction (SCR), it has advantages of high denitration efficiency and N2selectivity.
对多元金属氧化物基本性质的研究表明，多元金属氧化物中主要有Fe、Si、Al等多种元素，颗粒表面存在Si、Na、Al、V等元素的富集。多元金属氧化物比表面积极低，基础脱硝活性较低，不适合直接作为脱硝催化剂或者活性组分。
制备了XO为催化剂基体，TiO2为载体，Fe2O3为活性组分的催化剂，考察基体对催化剂的影响。实验结果表明，加入多元金属氧化物后，催化剂比表面积减小、氧化性增强。在250℃-350℃内催化剂的脱硝活性在90 %以上，但是活性温窗较窄。分别使用CeO2、MoO3、WO3对催化剂进行掺杂，实验结果表明：掺杂后催化剂比表面积增大，有利于氨气的吸附，促进SCR反应的进行；CeO2掺杂后催化剂的脱硝活性在整体上提高，但是最佳活性温窗没有变宽或者变化；MoO3、WO3掺杂后催化剂的中低温活性降低，高温活性Fra Baidu bibliotek高，活性温窗宽，并向高温移动。
First, a series of experiments were conducted to research denitration catalyst based on Fe, including the preparation method and the content of CeO2. The catalysts were characterized with XRD, XPS, H2-TPR, BET and UV-Vis DRS, and the denitration activity and the oxidation rate of NH3over catalysts was evaluated. Then, the basic properties of multiple metal oxide were characterized by the means of XRD, XPS, XRF, BET, and the basic denitration activity of multiple metal oxide was studied. Non supported catalysts was prepared with XO, TiO2, Fe2O3as base material, carrier and active constituent respectively. The effects of XO and different assistant on the SCR catalytic activity was investigated.
本文首先考察了制备方法、助剂CeO2含量两个因素对非负载型Fe2O3催化剂性能的影响。通过XRD、XPS、H2-TPR、BET比表面积测试、UV-vis DRS等表征手段，对催化剂进行了表征，并且对催化剂的脱硝活性和对氨气的氧化率进行评价。然后，通过XRD、XPS、XRF、BET比表面积测试的表征手段，分析了一种工业级多元金属氧化物(MO)的基本性质，研究了其基础脱硝活性。以XO为催化剂基体，TiO2为载体，Fe2O3为活性组分制备了负载型脱硝催化剂。考察了XO及不同助剂对SCR催化活性的影响。利用XRD、H2-TPR、BET比表面积测试等技术对制备的催化剂进行了表征。
At present, there exist some problems in the commercial catalyst, the price is expensive, narrow active temperature window, and abandoned catalyst will lead to secondary pollution. So, it has very important significance to develop environmental friendly catalyst, low temperature, high efficiency and cheap. Iron oxide, has received the attention of scholars both at home and abroad, because it has advantages of environmentally friendly, low prices,and strong reducibility.This paper focuses on the preparation and characterization of denitration catalystbased on Fe.
铁基中低温SCR脱硝催化剂性能研究
摘
氮氧化物(NOx)对人体、环境的危害很大，是目前国内外急需解决的问题之一。选择性催化还原法具有脱硝效率高、N2选择性好等优点，得到广泛使用。商业化的脱硝催化剂存在价格昂贵，活性温窗窄，活性窗口温度较高且废弃的催化剂易造成二次污染等问题，所以，开发廉价、低温、高效的环境友好型催化剂具有十分重要的意义。铁的氧化物具有环境友好、价格低廉以及还原性强等优点，在NOx选择催化还原(SCR)脱除领域已经受到了国内外学者的广泛关注。本文主要针对氧化铁脱硝催化剂的制备、表征等各方面进行了研究。
关键词：选择性催化还原，多元金属氧化物，氧化铁，脱硝
ABSTRACT
In recent years, with the rapid development of industrialization in China, atmospheric pollution caused by the burning of fossil fuels has being more and more serious. NOx is one of the main atmospheric pollutants, which bring huge harm to human body and environment, it is one of the urgent problems at home and abroad to be solved. There are many methods controlling NOx emission，one of the most widely used is selective catalytic reduction (SCR), it has advantages of high denitration efficiency and N2selectivity.