本文關(guān)鍵詞： NOx選擇性還原和CO氧化 Sn和Cu分子篩 多形貌SnO2和ZnO 構(gòu)效關(guān)系 限域效應(yīng)　出處：《南昌大學(xué)》2015年碩士論文　論文類型：學(xué)位論文

【摘要】：近年來,隨著科學(xué)技術(shù)的日新月異,人們的生活水平不斷提高,然而不潔凈使用能源所帶來的環(huán)境污染卻愈來愈嚴(yán)重。大氣污染物中NOx和CO是兩類有毒有害氣體,消除它們的排放迫在眉睫。選擇性催化還原和催化氧化分別是消除NOx與CO排放的有效方法。本論文主要研究和探討NOx和CO凈化催化劑的設(shè)計(jì)與制備。第一部分首先研究了Sn-MFI分子篩的NOx催化脫除性能。研究結(jié)果表明,Sn離子成功摻雜進(jìn)入MFI分子篩骨架結(jié)構(gòu)中。Sn-MFI具有規(guī)整的形貌和結(jié)構(gòu),而且結(jié)構(gòu)中含有微孔-介孔多級孔道。同時(shí)Sn-MFI表面由于Sn離子介入形成大量的路易斯酸中心和表面活潑氧,因此,Sn-MFI具有良好的NOx選擇性還原活性和優(yōu)良的抗水和抗硫性能。為進(jìn)一步提高Sn-MFI的活性,第二部分著重研究了Sn-ZSM-5分子篩的NOx催化脫除性能。結(jié)果表明,相較于Sn-MFI分子篩,由于Al引入骨架,Sn-ZSM-5催化劑中形成了新的酸中心,且其酸性得到進(jìn)一步提高,因此,Sn-ZSM-5分子篩的NOx選擇性還原活性優(yōu)于Sn-MFI分子篩。論文的第三部分研究了片狀Cu-MFI分子篩的NOx催化脫除性能。結(jié)果表明,所制備的Cu-MFI納米片為形貌比較規(guī)整的納米片狀結(jié)構(gòu),具有微孔-介孔多級孔道結(jié)構(gòu)。隨著Cu含量的提高,反應(yīng)活性不斷增強(qiáng),最優(yōu)轉(zhuǎn)化NOx溫度窗口也相應(yīng)加寬。論文第四部分制備了多形貌SnO2納米新材料,然后應(yīng)用于CO催化氧化中,研究多形貌納米材料的構(gòu)效關(guān)系。研究結(jié)果表明,SnO2納米片具有高的比表面積、豐富的疏松的孔道、大量的表面活潑氧物種,因而具有優(yōu)良的CO催化氧化活性,260 oC可將CO完全轉(zhuǎn)化。SnO2單晶納米棒雖然比表面積只有1 m2g-1,但是由于其(110)活潑晶面優(yōu)先暴露,因此催化活性也大大提高,而且具有類貴金屬催化行為和機(jī)理,280 oC時(shí)可將CO完全轉(zhuǎn)化,并且在240-260 oC范圍內(nèi)出現(xiàn)明顯的反應(yīng)突躍。論文第五部分合成了ZnO納米管、納米片、納米棒和星型結(jié)構(gòu),探討ZnO納米材料的構(gòu)效關(guān)系。研究結(jié)果表明,與常規(guī)ZnO納米粉末相比,片狀ZnO的比表面積高達(dá)41 m2g-1,體相中存在大量的疏松孔道結(jié)構(gòu),對CO催化氧化具有很高的活性,在300 oC時(shí)即可將CO完全轉(zhuǎn)化。ZnO納米棒的比表面積僅為3 m2g-1,但是由于形成比較嚴(yán)整的單晶棒狀結(jié)構(gòu),改變了材料本來的電子性質(zhì)和催化機(jī)理,催化活性大大提高,在280 oC時(shí)可將CO完全轉(zhuǎn)化,而且在260-280 oC范圍內(nèi)出現(xiàn)了明顯的反應(yīng)突躍,具有類貴金屬反應(yīng)行為和機(jī)理。論文第六部分制備了纖維狀介孔SiO2(KCC-1)限域的CuO納米粒子,并應(yīng)用于NOx選擇性還原和CO氧化方面。研究表明,Cu-KCC-1對NOx選擇性還原和CO氧化都具有很高的催化活性。其活性中心為高度分散在KCC-1纖維狀結(jié)構(gòu)的表面、粒徑在10 nm以下的CuO顆粒,因而所得材料具有優(yōu)異的催化活性。
[Abstract]:In recent years, with the rapid development of science and technology, people's standard of living has been improved. However, the environmental pollution caused by the unclean use of energy is becoming more and more serious. NOx and CO are two kinds of toxic and harmful gases in the air pollutants. It is urgent to eliminate their emission. Selective catalytic reduction and catalytic oxidation are the effective methods to eliminate NOx and CO emissions respectively. The design and preparation of NOx and CO purification catalysts are studied and discussed in this paper. The first part is about the design and preparation of NOx and CO purification catalysts. The catalytic removal of Sn-MFI molecular sieve by NOx was studied. The results showed that Sn-MFI had regular morphology and structure in the skeleton structure of MFI molecular sieve. Moreover, there are micropore-mesoporous multistage channels in the structure. At the same time, a large number of Lewis acid centers and active oxygen are formed on the surface of Sn-MFI due to the involvement of Sn ions. Therefore, Sn-MFI has good NOx selective reduction activity and excellent water and sulfur resistance. In order to further improve the activity of Sn-MFI, the second part focuses on the study of NOx catalytic removal performance of Sn-ZSM-5 molecular sieve. The results show that, compared with Sn-MFI molecular sieve, Due to the introduction of Al into the framework Sn-ZSM-5 catalyst, a new acid center was formed, and its acidity was further improved. Therefore, the NOx selective reduction activity of Sn-ZSM-5 molecular sieve is superior to that of Sn-MFI molecular sieve. In the third part of this paper, the NOx catalytic removal performance of the flake Cu-MFI molecular sieve was studied. With the increase of Cu content, the reaction activity increases, and the temperature window of the optimal conversion NOx is widened accordingly. In the 4th part of the thesis, new multi-morphologies SnO2 nanomaterials were prepared. Then it was applied to CO catalytic oxidation to study the structure-activity relationship of multi-morphologies nanomaterials. The results showed that Sno _ 2 nanocrystals had high specific surface area, abundant porous pores and a large number of active oxygen species on the surface. Therefore, with excellent catalytic oxidation activity of CO, 260oC can completely transform CO into 路SnO2 nanorods, although the specific surface area of nanorods is only 1m2g-1, but because of the preferential exposure of their active crystal planes, the catalytic activity is also greatly improved. In addition, the ZnO nanotubes, nanorods, nanorods and starlike structures were synthesized in the 5th part of the thesis, and the CO was completely converted to CO at 280oC with noble metal catalytic behavior and mechanism, and the apparent reaction occurred in the range of 240-260oC. in the 5th part of the thesis, ZnO nanotubes, nanorods, nanorods and star structures were synthesized. The structure-activity relationship of ZnO nanomaterials was studied. The results showed that compared with conventional ZnO nano-powders, the specific surface area of flake ZnO was up to 41 m ~ (-2) g ~ (-1), and there were a large number of porous pore structures in bulk phase, which had high activity for CO catalytic oxidation. The specific surface area of ZnO nanorods was only 3m2g-1 when CO was completely transformed at 300oC. However, due to the formation of a more precise single crystal rod structure, the original electronic properties and catalytic mechanism of the materials were changed, and the catalytic activity was greatly improved. CO can be completely converted at 280oC, and there is a sharp jump in the range of 260-280oC, which has noble metal reaction behavior and mechanism. In the 6th part of this paper, CuO nanoparticles with the limited range of fibrous mesoporous SiO2KCC-1 have been prepared. The results show that Cu-KCC-1 has high catalytic activity for NOx selective reduction and CO oxidation. The active center of Cu-KCC-1 is highly dispersed on the surface of KCC-1 fibrous structure and the particle size is less than 10 nm. Therefore, the obtained material has excellent catalytic activity.
【學(xué)位授予單位】：南昌大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2015
【分類號】：X51;TQ426

【共引文獻(xiàn)】

相關(guān)期刊論文 前3條

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2 劉建軍;徐香蘭;劉文明;王翔;;不同鈰和鋯前體對鈰鋯固溶體性能的影響[J];南昌大學(xué)學(xué)報(bào)(理科版);2013年04期

3 王W，

本文編號：1524424