论文总字数：22088字

摘 要

氮氧化物（NO_x）是雾霾、酸雨和次生臭氧的主要成因，成为大气污染治理的重点。碳基材料因其发达的孔结构、高比表面积和优异的还原特性，分别在选择性催化还原（SCR）、直接催化分解和还原NOx中得到广泛应用。论文全面综述了不同碳基脱硝材料在SCR、直接催化分解及还原NO_x中的研究进展，以碳材料为载体的SCR催化剂表现出高效的低温脱硝活性，非金属元素掺杂的石墨烯能直接高效催化分解NO_x，活性炭可以直接还原NO_x为N₂和水蒸气。

本文面向NO_x治理的重大需求，设计构建了碳负载Cu-Ni双金属脱硝催化剂体系，以稀硝酸预处理后的活性炭为载体，浸渍Cu-Ni双金属前驱体溶液，优化干燥、烧成工艺，完成了Cu-Ni/AC催化剂的制备；分别测试评价了催化剂NH₃-SCR、直接催化分解和还原NO_x的效果，重点考察了氨氮比（NH₃/NO）、空速、氧含量和NO浓度等因素对Cu-Ni/AC脱硝性能的影响；并采用BET、FTIR、XRD和SEM等表征手段对催化剂的比表面、官能团结构、物相结构及微观形貌进行了分析。研究发现，稀硝酸可改善活性炭表面性质，改变表面官能团；采用共同浸渍法多次浸渍，可使活性组分均匀负载在载体表面；预测Cu-Ni/AC具有良好的低温催化活性，亦可有效降低反应活化能，进而降低直接催化分解和还原NO的活性温度。

关键词：氮氧化物治理 选择性催化还原 直接分解 碳还原 碳基材料

Preparation and properties study of new carbon-based denitrification material

Abstract

Nitrogen oxides (NO_x) is the main cause of haze, acid rain and secondary ozone, and has become the focus of air pollution control. Carbon-based materials are widely used in selective catalytic reduction (SCR), direct catalytic decomposition and reduction of NO_x respectively because of their developed pore structure, high specific surface area and excellent reduction properties. This paper comprehensively reviews the research progress of different carbon-based denitrification materials in SCR, direct catalytic decomposition and reduction of NO_x. SCR catalysts supported on carbon materials show efficient denitrification activity at low temperature. Graphene doped with non-metallic elements can directly and efficiently catalytically decompose NO_x, activated carbon and directly reduce NO_x to N₂ and water vapor.

In order to meet the great demand of NO_x treatment, a carbon-supported Cu-Ni bimetallic denitrification catalyst system was designed and constructed. The activated carbon pretreated with dilute nitric acid was used as the carrier, the Cu-Ni bimetallic precursor solution was impregnated, the drying and firing processes were optimized, and the Cu-Ni/AC catalyst was prepared. The effects of catalyst NH₃-SCR, direct catalytic decomposition and reduction of NO_x were tested and evaluated, with emphasis on the effects of ammonia-nitrogen ratio (NH₃/NO), space velocity, oxygen content and NO concentration on Cu-Ni/AC denitrification performance, and the specific surface area, functional group structure, phase structure and micro-morphology of the catalyst were analyzed by BET, FTIR, XRD and SEM. It is found that dilute nitric acid can improve the surface properties of activated carbon and change the surface functional groups; the active components can be uniformly loaded on the surface of the carrier by co-impregnation method for many times; it is predicted that Cu-Ni/AC has good catalytic activity at low temperature, and can also effectively reduce the reaction activation energy, thus reducing the activity temperature of direct catalytic decomposition and reduction of NO.

Key Words: Nitrogen oxide treatment ; Selective catalytic reduction; Direct decomposition; Carbon reduction; Carbon-based materials

目 录

摘 要 I

Abstract II

第一章 绪论 1

1.1 课题研究背景 1

1.1.1 氮氧化物的来源 1

1.1.2 氮氧化物的组成与危害 2

1.2 氮氧化物的排放控制技术 2

1.2.1 工业脱硝技术 2

1.2.2 选择性催化还原法 3

1.2.3 选择性非催化还原法 4

1.2.4 直接催化分解法 4

1.2.5 碳还原 5

1.3 碳基材料 6

1.4 研究内容及意义 7

1.4.1 研究内容 7

1.4.2 研究意义 8

第二章 实验方案 9

2.1 实验原料及仪器 9

2.2 负载Cu-Ni活性炭的制备 9

2.2.1 活性炭的预处理 9

2.2.2 负载Cu和Ni双金属 10

2.3 脱硝性能测试 10

2.4 材料表征与测试 11

第三章 实验结果及分析 13

3.1 材料表征分析 13

3.1.1 BET分析 13

3.1.2 FTIR图谱 13

3.1.3 XRD分析 14

3.1.4 SEM分析 14

3.2 选择性催化还原反应中Cu-Ni/AC的性能研究 15

3.2.1 氨氮比对Cu-Ni/AC在SCR中催化活性的影响 15

3.2.2 氧含量对催化剂在SCR中催化活性的影响 15

3.2.3 空速对催化剂在SCR中催化活性的影响 16

3.2.4 SCR反应机理研究 17

3.3 直接催化分解反应中Cu-Ni/AC的性能研究 17

3.3.1 NO浓度对催化剂催化活性的影响 17

3.3.2 空速对催化剂催化活性的影响 18

3.3.3 氧含量对催化剂催化活性的影响 18

3.3.4 浸渍顺序对催化剂催化活性的影响 19

3.3.5 直接催化分解反应机理研究 19

3.4 碳还原反应中Cu-Ni/AC的性能研究 20

3.4.1 硝酸处理及负载金属对碳还原NO的影响 20

3.4.2 反应时间对碳还原NO的影响 22

3.4.3 氧含量对碳还原NO的影响 22

第四章 结论与展望 24

4.1 结论 24

4.2 展望 24

参考文献 25

第一章 绪论

1.1 课题研究背景

1.1.1 氮氧化物的来源

从上个世纪后期到本世纪初期，在我国城市化规模不断扩大，工业生产持续增加的同时，环境污染问题愈发严重。国家为此专门制定了一系列环境保护政策，社会各界都积极响应国家号召，自此，环境保护成为不可无视的事业。

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