Characterization of Wood Chars Produced at Different Temperatures Using Advanced Solid-State 13C NMR Spectroscopic Techniques

阅读量:

65

作者:

X CaoJJ PignatelloY LiC LattaoMA ChappellN ChenLF MillerJ Mao

展开

摘要:

Temperature is one of the controlling factors determining the chemical structure of char. We employed advanced solid-state 13C NMR techniques to characterize maple wood and its chars produced under N2 at temperatures from 300 to 700 °C. Our results indicated that 300 °C char was primarily composed of residues of biopolymers such as lignin and cellulose. Carbohydrates are completely lost for char prepared at 350 °C. At 400 °C, the char lost most of the ligno-cellulosic features and consisted predominantly of aromatic structures. By 500 °C, sp3-hybridized carbon had all but disappeared. Protonated aromatic carbons increased up to 400 °C chars but then decreased. Aromatic C–O groups decreased, whereas nonprotonated aromatic carbons, especially bridgehead carbons, increased as temperature increased. The minimum aromatic cluster sizes estimated from spectral analysis increased from 8 carbons in 300 °C char, to 20, 18, 40, 64, and 76 carbons, respectively, in 350 °C, 400 °C, 500 °C, 600 °C, and 700 °C chars. 1H–13C long-range dipolar dephasing displayed the same increasing trend of aromatic cluster sizes of wood chars with increasing temperature. We show for the first time quantitative changes of different aromatic C forms and aromatic cluster size as a function of heat treatment temperature.

展开

DOI:

10.1021/ef300947s

被引量:

73

年份:

2012

通过文献互助平台发起求助,成功后即可免费获取论文全文。

相似文献

参考文献

引证文献

来源期刊

引用走势

2015
被引量:18

站内活动

辅助模式

0

引用

文献可以批量引用啦~
欢迎点我试用!

关于我们

百度学术集成海量学术资源,融合人工智能、深度学习、大数据分析等技术,为科研工作者提供全面快捷的学术服务。在这里我们保持学习的态度,不忘初心,砥砺前行。
了解更多>>

友情链接

百度云百度翻译

联系我们

合作与服务

期刊合作 图书馆合作 下载产品手册

©2025 Baidu 百度学术声明 使用百度前必读

引用