摘 要

随着工业的迅速发展，汽车尾气、燃煤电厂和硝酸制造工厂的氮氧化物（NOx）排放量也迅速增加，对生态环境的破坏越来越大，所以对氮氧化物的去除也迫在眉睫。目前去除工业排放的烟气中的氮氧化物的方法主要是选择性催化还原（SCR）。催化剂是SCR技术的核心技术部分，其性能可以直接影响SCR系统的脱硝效率，因此开发性能优异的催化剂是非常必要的。研究表明，通过引入大比表面积的碳材料，可以有效地提高催化剂的低温反应活性。但是碳纳米管分散性差，故而需要使用表面活性剂对其进行改性。本论文以表面功能化的碳纳米管（CNTs）为载体，通过原位生长的方法在其表面负载V₂O₅活性物质，使用表面活性剂对碳纳米管进行改性，使用CPC辅助回流法制得了V₂O₅/CNTs脱硝催化剂。采用XRD、TEM、BET、NH₃-TPD等测试方法对制备的样品进行结构和形貌表征，比较了制备的脱硝催化剂的结构特征及脱销性能。论文主要研究表面活性剂含量的不同对于制备的脱硝催化剂的表面酸性位酸性的影响规律。最终发现表面活性剂与碳纳米管之比为2:1 时制得的脱硝催化剂的表面酸性位的数量和强度是最高的，脱硝的性能也是最好的。

关键词：碳纳米管，钒氧化物，原位生长，SCR，表面活性剂

Abstract

With the rapid development of industry, the emissions of nitrogen oxides (NOx) from automobile exhaust, coal-fired power plants, and nitric acid manufacturing plants have also rapidly increased and the ecological environment has become increasingly destructive. Therefore, the removal of nitrogen oxides is imminent. The current method of removing nitrogen oxides from industrially emitted flue gas is mainly selective catalytic reduction (SCR). The catalyst is the core technology part of the SCR technology, and its performance can directly affect the denitration efficiency of the SCR system. Therefore, it is very necessary to develop a catalyst with excellent performance. Studies have shown that by introducing a large specific surface area of carbon material, the low temperature reaction activity of the catalyst can be effectively improved. However, carbon nanotubes are poorly dispersed, so they need to be modified by surfactants. In this paper, surface functionalized carbon nanotubes (CNTs) were used as carriers, and V2O5 was loaded on the surface of CNTs by in situ growth method. Surfactants were used to modify CNTs, and CPC-assisted reflux method was used to prepare V2O5/CNTs denitrification catalyst.XRD, TEM, BET and NH3-TPD were used to characterize the structure and morphology of the prepared samples, and the structural characteristics and desalination performance of the prepared catalysts were compared.. n this paper, the effect of surfactant content on the acidity of surface acidity of denitrification catalyst was studied.. It was found that the amount and strength of the surface acidity sites of the denitrification catalyst prepared at the ratio of surfactant to carbon nanotubes was the highest, and the denitrification performance was the best.

Keywords: carbon nanotubes, vanadium oxide, in situ-growth, SCR

目 录

第1章 绪论 1

1.1 引言 1

1.2 氮氧化物控制技术 1

1.2.1 焚烧前的氮氧化物控制技术 2

1.2.2 燃烧中的氮氧化物控制技术 3

1.2.3 燃烧后的处理技术 3

1.3 SCR催化剂研究现状 4

1.3.1 SCR催化剂类型 4

1.3.2 钒钛脱硝催化剂的载体类型 5

1.4 碳纳米管的表面功能化 6

1.4.1 阴离子表面活性剂改性研究 7

1.4.2 阳离子表面活性剂改性研究 7

1.4.3 两性表面活性剂改性研究 7

1.5 本文研究的目的及意义 8

第2章 V₂O₅/CNTs脱硝催化剂的制备及表征 9

2.1实验试剂及仪器 9

2.1.1实验试剂 9

2.1.2 实验仪器 9

2.2 V₂O₅/CNTs脱硝催化剂的制备 9

2.2.1碳纳米管的纯化 9

2.2.2 V₂O₅/CNTs脱硝催化剂的制备 10

2.3 V₂O₅/CNTs脱硝催化剂的表征 10

.2.3.2显微结构分析 11

2.3.3程序升温脱附法 11

2.3.4催化剂活性测定 11

第3章 V₂O₅/CNTs催化剂的结构与脱硝性能 12

3.1 V₂O₅/CNTs脱硝催化剂的结构分析 12

3.1.1 CPC含量对催化剂结构的影响 12

3.1.2 V₂O₅/CNTs催化剂的原位生长机理分析 14

3.1.3 CPC含量对催化剂表面酸性的影响 15

3.2 V₂O₅/CNTs催化剂的脱硝性能分析 16

3.2.1 CPC含量对催化剂SCR脱硝活性的影响 16

3.2.2催化剂结构与SCR活性相关性分析 17

第4章 结论与展望 18

4.1结论 18

4.2展望 18

参考文献 19

致谢 21

第1章 绪论

1.1 引言

现如今，如何管理大气的污染问题已经成为每个国家需要解决的问题。臭氧层空洞的出现意味着整个世界的大气的问题已经相当严重，北京灰霾天气一再出现，PM2.5成为众所周知的一个词语，种种现象都在告诉着我们我国的大气污染问题。因此管理大气污染已经是燃眉之急的事情了。