期刊
ACS SUSTAINABLE CHEMISTRY & ENGINEERING
卷 9, 期 8, 页码 3095-3103出版社
AMER CHEMICAL SOC
DOI: 10.1021/acssuschemeng.0c07460
关键词
thermal decomposition; glycerol; pyrolysis; pyridine; pyridine synthesis
资金
- Jiangsu Province 333 Project [BRA2019277]
- CAS Key Laboratory of Renewable Energy [Y907k41001]
- Six Talent Peaks Project in Jiangsu Province [XNY-007]
- Foundation of State Key Laboratory of Coal Combustion [FSKLCCA1904]
In this study, glycerol was used to synthesize pyridine, and it was found that neutral glycerol could be directly converted into pyridine in an ammonia atmosphere. The research confirmed the conversion mechanism with experimental data and theoretical modeling. Additionally, the ZSM-5 catalyst played a role in shape-selectivity and altering the reaction pathway for glycerol conversion to pyridine.
In the present study, glycerol was exploited as the feedstock to synthesize pyridine with ammonia gas as a carrier and reactant through thermal conversion. A density functional theory (DFT) at the M06-2X method was applied to understand the mechanism of glycerol dehydration, the ammonization of oxygenated compounds, and the condensation of imines. The results confirmed that glycerol could be directly converted into pyridine in ammonia atmosphere at 550 degrees C. The overall view of the thermal conversion mechanism of glycerol was compared with the previous experimental data and the proposed mechanisms, which indicated that the neutral glycerol dehydration process should mainly produce acrolein, acetaldehyde, formaldehyde, and acetol. The produced oxygenated compounds (acrolein and acetaldehyde) can react with ammonia to form imine, which would further undergo Michael addition, a Diels-Alder reaction, deammonization, and dehydrogenation to form pyridine. In a catalytic condition, ZSM-5 not only plays a shape-selective effect on the conversion of glycerol to pyridine but also changes the path of the reaction. The structure of ZSM-5 limits the formation of multisubstituted pyridine products, which is beneficial to the formation of pyridine and monosubstituted pyridine. Protonated vinylamine intermediates may be a critical step limiting pyridine yield and selectivity. The kinetic analysis that is based on transition state theory was consistent with product contribution in experiments. The present study confirmed the selectivity and the conversion route of glycerol to pyridine.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据