论文总字数：27442字

摘 要

近年来，氮氧化物(NO_x)已成为大气污染的主要污染物之一，严重危害人类的健康和地球的生态环境。目前烟气脱硝是国家“十二五”大气污染治理的重点，因此控制NO_x已成为治理大气刻不容缓的一项任务。选择性催化还原脱硝技术效率高、稳定性能好，已成为当前工业应用研究的主流和发展方向。因此，研发与之相匹配的低温高效、性能稳定的SCR催化剂成为该NO_x控制技术研究发展的关键。然而，催化剂中毒始终制约低温SCR催化剂的使用寿命和产业化进程。尤其是低温烟气中SO₂易导致催化剂中毒失效，从而影响其活性。

本论文以Mn-Ce基低温脱硝催化剂为研究对象，通过掺杂 Cu，Co，Fe，Ni，La，Zr六种过渡金属，测试其在SO₂存在下对NO_x的转化率，研究了不同过渡金属掺杂对Mn-Ce基催化剂抗SO₂性能的影响，确立了最佳掺杂元素；并通过对最佳掺杂元素掺入比例的优化，确立了最佳掺杂比例。结果表明，使用Fe掺杂的Mn-Ce基脱硝催化剂低温抗SO₂效果最好，当Mn:Ce:Fe=5:1:1.2，在150ppm的SO₂的条件下，催化剂对NO_x的转化率仍可达到86%。

关键词：脱硝 Mn-Ce-O_x催化剂 抗SO₂性能 过渡金属掺杂

Promotional effect of transition metal ions doping on anti- SO₂ poisoning ability of Mn-Ce-O_x Catalysts at low temperature

Abstract

NO_x has been the main atmospheric pollutant recently, seriously affecting human’s health and the earth environment. Flue gas denitration is currently the focus of national five-year atmospheric pollution control. So, it’s an urgent task to control NO_x. Selective catalytic reduction denitration technology with high efficiency, good stable performance has become the mainstream of current industrial application research and developing direction. Therefor, research and development to match the high efficiency and stable performance in low-temperature SCR catalysts has become the key to the research and development of the NO_x control. However, the catalyst poisoning always restrict the use life and industrialization of low-temperature SCR catalyst. Especially, SO₂ in flue gas at low temperature can cause catalyst poisoning failure, which affects its’ activity.

The low-temperature Mn-Ce based denitration catalyst is taken as the research object in this paper. By doping Cu, Co, Fe, Ni, La, Zr into Mn-Ce based catalysts, I have tested the six kinds of catalysts’conversion rate on NO_x in the presence of SO₂ and studied the effects of the different transition metal on the anti-SO₂ ability of Mn-Ce based catalysts to select the optimal doping element. With the optimization of the proportion of the Mn-Ce-O_x catalysts doped by the optimal doping elements, I have determined the optimal doping ratio. The results show that the Mn-Ce-O_x denitration catalyst doped by Fe has the best anti-SO₂ activity at low temperature. when Mn:Ce:Fe=5:1:1.2 in presence of 150ppm SO₂, the catalyst’s conversion rate on NO_x can still reach 86%.

Key words：denitration; Mn-Ce-O_x catalyst; anti-SO₂ ability; transition metal ions doping

目 录

摘 要 I

Abstract II

第一章 引言 1

1.1 氮氧化物 1

1.1.1 氮氧化物来源及现状 1

1.1.2 氮氧化物危害 1

1.1.3 氮氧化物治理 2

1.2 选择催化还原技术（SCR） 3

1.2.1 选择催化还原技术简介 3

1.3 SCR催化剂及其研究现状 4

1.3.1 SCR催化剂反应机理 4

1.3.2 贵金属催化剂 5

1.3.3分子筛催化剂 6

1.3.4金属氧化物催化剂 6

1.4 问题及展望 8

1.5 课题来源及研究内容 9

1.5.1 课题来源 9

1.5.2 研究内容 10

第二章 实验技术与方法 11

2.1 化学试剂和仪器 11

2.2 催化剂的制备 12

2.2.1 Mn-Ce基催化剂制备 12

2.2.2过渡金属掺杂Mn-Ce基催化剂的制备 12

2.3 催化剂评价系统 12

2.3.1 催化剂活性评价测试台 12

2.3.2 催化剂活性评价条件 13

2.3.3 催化剂活性测试流程 14

第三章 实验数据及结果分析 15

3.1过渡金属掺杂的Mn-Ce基催化剂 15

3.1.1过渡金属掺杂的Mn-Ce催化剂与纯Mn-Ce催化剂的比较 15

3.1.2 最佳掺杂元素的选择 18

3.1.3 不同掺杂量对Mn-Ce催化剂催化活性的影响 18

第四章 结论与展望 26

4.1 结论 26

4.2 展望 26

参考文献 28

致谢 31

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