g-C3N4催化剂的制备改性及其催化CH4、CO2重整反应的研究

论文总字数：25487字

摘 要

随着化石燃料的需求量越来越大，地球上的化石燃料日益枯竭，寻找新的能源来替代化石能源已经是全人类面临的新时代问题。同时，化石燃料的大量使用造成了严重的环境问题，不利于经济、环境、社会的可持续发展。本文通过对g-C₃N₄催化剂在CO₂/CH₄重整反应中的研究，发现g-C₃N₄催化剂能有效的将太阳能转化成化学能储存在化学物质中，不仅解决了能源危机，还能够在一定程度上减少大气中CO₂的含量，缓解温室效应。

本文主要针对新型的g-C₃N₄以及其改性后催化剂在CH₄、CO₂光催化重整反应中的应用展开研究。通过对不同方法制备的g-C₃N₄和改性后的g-C₃N₄进行了傅立叶红外光谱仪（FTIR Spectrometer）、组合型多功能水平X射线衍射仪（XRD）、紫外可见分光光度计（UV-vis）、Sirion 场发射扫描式电子显微镜（SEM）、透射式电子显微镜（TEM）测试，分别分析了g-C₃N₄催化剂的组成、结构、性质以及催化效率与结构之间的联系。

催化剂的主要成分是g-C₃N₄、Zn和Ru，改变三者之间的配比可以制备出不同性质的催化剂。然后，以CO₂、CH₄为原料气在太阳光模拟器里面进行反应，通过气相色谱分别定性和定量分析出产物的成分和产物的产量。以催化剂组成成分作为对象，经过一系列的梯度实验之后，找出三者之间的最优配比。经过对不同配比的催化剂进行表征，对比产率和结构之间的关系，分析出催化剂的结构和性质之间的内在联系。

将CO₂、CH₄作为原料气，在催化剂的条件下进行光催化反应，将混合气体通入气相色谱，在进行标样对比分析后，得出反应的主要产物是CH₃CH₂OH、CH₃CHO和 CO。通过对催化剂的微观结构、反应物和产物进行分析，最终推断出该光催化反应的基理。本文关于g-C₃N₄以及其改性后催化剂的理论研究对CO₂/CH₄重整反应有一定的指导意义。

关键词：g-C₃N₄，光催化，二氧化碳，甲烷

Abstract

With the increasing demand for fossil fuels, finding new energy sources to replace fossil fuels is already a new era problem for humanity. At the same time, excessive use of fossil fuels has caused serious environmental problems, which is not conducive to the sustainable development of economy, environment and society. In this paper, by studying the function of g-C₃N₄ catalyst in the CO₂/CH₄ reforming reaction, it was found that g-C₃N₄ catalyst can effectively convert solar energy to chemical energy and store it in chemical substances. It not only solves the energy crisis, but also reduces the content of CO₂ in the atmosphere in a certain extent and alleviate the greenhouse effect.

This article mainly focuses on the application of novel g-C₃N₄ and modified g-C₃N₄ catalysts in the photocatalytic reforming of CH₄ and CO₂. The FTIR Spectrometer (Nicolet 5700), XRD (Ultima Ⅳ), UV (UV-2600), SEM and TEM tests were performed on g-C₃N₄ and modified g-C₃N₄ catalysts prepared by different methods. The composition, structure, properties and the relationship between catalytic efficiency and structure of g-C₃N₄ and modified g-C₃N₄ catalysts have been discussed.

The main components of the catalyst are g-C₃N₄, ZnO and Ru. Changing the ratio among the three components can produce catalysts with different properties. Then, CO₂ and CH₄ were used as raw materials to react under simulated solar energy. The product composition and yield were qualitatively and quantitatively analyzed by gas chromatography. Regarding the catalyst composition as an object, we can find out the optical ratio of three gradients after a series of experiments. After comparing the relationship between yield and the structure and characterizing the catalyst with different ratio, we can analyze the intrinsic relationship between structure and the property of the catalyst.

Using CO₂ and CH₄ as raw materials, the photocatalytic reaction was carried out with the catalyst. Then, the mixed gas was passed into the gas chromatography. After preparing with the standard sample, the main products of the reaction were CH₃CH₂OH and CH₃CHO, with a small amount of byproduct CO. By analyzing the microstructure, reactants and products of the catalyst, the basic principle of the photocatalytic reaction was finally deduced. The theoretical study of g-C₃N₄ and its modified catalyst in this passage has a certain guiding significance for the CO₂/CH₄ reforming reaction.

KEY WORDS: g-C₃N₄, photocatalytic, carbon dioxide, methane

目 录

摘 要 I

Abstract II

第一章 绪论 1

1.1 g-C₃N₄的研究现状 1

1.2 g-C₃N₄的制备方法 2

1.3 CH₄光还原CO₂的研究进展 3

1.4 改性g-C₃N₄催化剂的研究进展 4

1.4.1掺杂改性 4

1.4.2半导体光催化剂形貌改性 5

1.4.3半导体复合改性 5

1.5 本章小结 5

第二章 催化剂的制备 6

2.1 实验药品及仪器 6

2.1.1实验药品 6

2.1.2实验仪器 6

2.2 催化剂的制备过程 6

2.2.1催化剂的制备步骤 6

2.2.2催化剂的种类 8

2.3标样制备过程及结果 8

2.4催化剂的活性测试 9

2.4.1光催化活性测试 9

2.4.2光催化活性测试结果 10

2.5 本章小结 11

第三章 催化剂表征 12

3.1 X射线衍射图谱（XRD） 12

3.2 扫描电子显微镜（SEM）和透射电子显微镜（TEM） 13

3.2.1扫描电子显微镜 13

3.2.2透射电子显微镜 14

3.3 傅立叶红外光谱（FTIR） 14

3.4紫外-可见吸收光谱（UV-vis） 15

3.5 本章小结 16

第四章 结果与展望 17

致 谢 19

参考文献 20

第一章 绪论

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