| 引用本文: | 曹元甲,张智文,王震,卢翠英.原位催化热解煤沥青生长毫米级多壁碳纳米管[J].材料科学与工艺,2021,29(5):23-36.DOI:10.11951/j.issn.1005-0299.20210076. |
| CAO Yuanjia,ZHANG Zhiwen,WANG Zhen,LU Cuiying.In-situ growth of millimeter-sized MWCNTs from coal tar pitch by catalytic pyrolysis[J].Materials Science and Technology,2021,29(5):23-36.DOI:10.11951/j.issn.1005-0299.20210076. |
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| 摘要: |
| 本文提出一种以煤沥青(CTP)为碳源,乙酸镍为催化剂前驱体,简单通用的多壁碳纳米管(MWCNTs)催化热解生长工艺。借助SEM、TEM、Raman及TGA等分析手段对样品微观形貌结构、缺陷度及含量进行表征,系统探索了温度、催化剂用量及生长时间对MWCNTs含量、晶体缺陷、长径比的影响规律。结果表明:Ni催化生长的MWCNTs壁厚约10 nm,管径几十纳米；850~1 000 ℃范围内,随温度升高,拉曼光谱中D1峰和G峰强度比(ID1/IG)由0.95减小到0.92再增大到1.02；热重测试DTG拟合分析表明CNTs和无定型碳含量的峰面积比S2/S1比值变化也有类似趋势；当Ni的质量分数为0~0.75%,MWCNTs随Ni含量的增加而增多；延长热解时间有利于MWCNTs生长,950 ℃,0.75%Ni时,催化热解CTP 3 h制备的MWCNTs长度可达毫米级。在综合分析和TEM表征基础上,认为CTP催化热解生长MWCNTs时,为顶端和底端机理并存过程。 |
| 关键词: MWCNTs 生长机理 催化热解 煤焦油沥青 乙酸镍 |
| DOI：10.11951/j.issn.1005-0299.20210076 |
| 分类号:TB383 |
| 文献标识码:A |
| 基金项目:国家自然科学基金资助项目 (21763029);榆林科技局项目 (2019-82-2);榆林高新区管委会项目;榆林学院研究生创新基金项目(2020YLYCX01). |
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| In-situ growth of millimeter-sized MWCNTs from coal tar pitch by catalytic pyrolysis |
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CAO Yuanjia, ZHANG Zhiwen, WANG Zhen, LU Cuiying
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(School of Chemistry and Industrial Engineering,Yulin University,Yulin 719000, China)
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| Abstract: |
| A simple and universal process for the growth of multi-walled carbon nanotubes (MWCNTs) by catalytic pyrolysis was developed using coal tar pitch(CTP) as carbon source and nickel acetate as catalyst precursor.By means of SEM, TEM, Raman, and TGA, the microstructure, defect degree, and content of the samples were characterized. The effects of temperature, catalyst dosage, and growth time on the content, crystal defect, and length-diameter ratio of MWCNTs were systematically explored.Results show that the wall thickness of Ni-catalyzed MWCNTs was about 10 nm, and the diameter was tens of nanometers.In the range of 850 to 1 000 ℃, as the temperature increased, the intensity ratio of the D1 peak to the G peak in the Raman spectrum (ID1/IG) decreased from 0.95 to 0.92 and then increased to 1.02.The DTG fitting analysis of thermogravimetric test shows that the changes in the peak area ratio S2/S1(S2 and S1 represent the peak area of CNTs and amorphous carbon content respectively) had a similar trend.When the Ni content was 0~0.75% (mass fraction), MWCNTs increased with increasing Ni content.Prolonging the pyrolysis time was beneficial to the growth of MWCNTs. At 950 ℃ and with 0.75%Ni, the length of MWCNTs prepared by catalytic pyrolysis of CTP for 3 h couldreach the millimeter level.Based on the comprehensive analysis and TEM characterization, it is concluded that there is a coexistence of top and bottom mechanisms during the growth of MWCNTs from CTP by catalytic pyrolysis. |
| Key words: MWCNTs growth mechanism catalytic pyrolysis coal tar pitch nickel acetate |
