cufe2o4催化剂的制备、表征及其脱硝性能研究-化学工程专业毕业论文.docx

硕士论文 CuFe20。催化剂的制备、表征及其脱硝性能研究
摘 要
氮氧化物州0x)是重要的大气污染物之一。、
载型催化剂在SCR中催化活性高而受到了极大的关注。“、CuFe204/SBA一1 5
催化剂,。通过X射线衍射光谱(XRD)、扫描电子显微镜(SEM)、透射电镜(TEM)、程序升温脱附(TPD)、X射线光电子能谱(xPs)等分析测试方法对催化剂的结构及性质进行了研究。
实验结果表明,以PS球为模板剂、草酸铵为沉淀剂制备的CuFe204催化剂比用氨水为沉淀剂制备的CuFe204及以PVP为模板制备的样品表现了更加优越的催化活性, 在240℃~330℃间有85%的脱硝活性。XRD结果表明不同方法合成的CuFe204样品结晶性能良好,检测到有少量Fe203生成。TEM图证实制备样品呈空心球状。
。催化剂,Fe:Cu=2:1的样品在180~330℃间表现出色的活性,氮氧化物脱除率约98%。,只有CuFe204负载量高于25%时,CuFe204特征峰才能被检测到。XPS研究表明,当Fe:Cu=2:1时,催化剂含有最多的化学吸附氧,原位漫反射证实催化剂在无氧环境下对NO和NH3有氧化活性。采用XPS深入分析了催化剂表面化学吸附氧的性质及对催化活性的影响,用原位漫反射研究了NO和NH3在催化剂上的吸附和反应,基于此得到了SCR反应模型。
,, 会产生Br6nsted酸,进一步提高催化活性,脱硝率在480℃能达到100%。小角XRD 结果表明了制备样品具有介孔结构。TEM图展现了样品具有秩序井然的介孔阵列。—SBA一15催化剂展现了优越的抗硫性能。红外结果表明硫物种存在形态主要是硫酸盐或硫酸氢盐,XPS结果表明硫存在S厶和S6+两种价态。
关键词:脱硝;选择性催化还原;CuFe204;化学吸附氧;反应过程
万方数据
硕士论文 CuFe20。催化剂的制备、表征及其脱硝性能研究
Abstract
Nitrogen oxides(NOx)are one of the important atmospheric iron—based spinel and ZSM·5,SBA一1 5 molecular sieve supported catalyst have attracted a great deal of
concern because of its high catalytic activity in the SCR reaction.
In this paper,unsupported CuFe204 catalyst and supported Fe—CuOx/ZSM·5,
CuFe204/SBA-1 5 catalysts were prepared,and the NH3一SCR performance of these catalysts Was tested in a fixed—bed ,SEM,TEM,TPD,XPS and other characterization methods were used to characterize the structure and properties of catalysts.
The experiment results showed that,catalyst prepared by PS spheres,processed by ammonium oxalate had a higher NOx conversion of 85%range from 240 to 330 than other samples mainly due to its rough showed that CuFe204 prepared by different
methods had high crystallinity,diffraction peaks of Fe203 also can be
micrographs indicated that the prepared samples exhibited hollow spherical structure。
For Fe—CuOx/ZSM