无机盐工业
主管:中海油天津化工研究设计院有限公司
主办:中海油天津化工研究设计院有限公司
   中海油炼油化工科学研究院(北京)有限公司
   中国化工学会无机酸碱盐专业委员会
ISSN 1006-4990 CN 12-1069/TQ

无机盐工业 ›› 2023, Vol. 55 ›› Issue (12): 82-87.doi: 10.19964/j.issn.1006-4990.2023-0059

• 研究与开发 • 上一篇    下一篇

二甲基一氯硅烷和三氯氢硅的热氯化反应及机理研究

段锐(), 贾朝航, 徐茂兰, 马天悦, 彭文才(), 张建树()   

  1. 石河子大学化学化工学院,化工绿色过程省部共建国家重点实验室培育基地,新疆 石河子 832003
  • 收稿日期:2023-02-08 出版日期:2023-12-10 发布日期:2023-12-14
  • 通讯作者: 彭文才(1980— ),男,副教授,主要研究方向为多相催化;E-mail: pengwencai@shzu.edu.cn
    张建树(1979— ),男,教授,主要研究方向为多晶硅工艺;E-mail: zjschem@163.com
  • 作者简介:段锐(1996— ),男,硕士,主要研究方向为多晶硅工艺;E-mail: ruiduan_quan@163.com
  • 基金资助:
    兵团重大科技项目(2017AA007);八师石河子市重大科技项目(2020ZD02)

Study on thermal chlorination and mechanism of chlorodimethylsilane and trichlorosilane

DUAN Rui(), JIA Zhaohang, XU Maolan, MA Tianyue, PENG Wencai(), ZHANG Jianshu()   

  1. School of Chemistry and Chemical Engineering State Key Laboratory Incubation Base for Green Processing of Chemical Engineering,Shihezi University,Shihezi 832003,China
  • Received:2023-02-08 Published:2023-12-10 Online:2023-12-14

摘要:

去除三氯氢硅(SiHCl3)中的碳杂质可提高多晶硅的纯度,但SiHCl3和二甲基一氯硅烷[(CH32SiHCl]的沸点极为接近,在精馏过程中易形成共沸物。因此,SiHCl3中的(CH32SiHCl较难去除。提出以Cl2为氯源,通过热氯化反应将(CH32SiHCl转化为高沸点的甲基氯硅烷,以增大相对挥发度,便于后续精馏除杂。但(CH32SiHCl和SiHCl3会同时发生氯化反应,为此,探究了两者转化率随温度的变化。结果表明,在60 ℃、120 min时,(CH32SiHCl的转化率为53.1%,SiHCl3的转化率为14.3%,(CH32SiHCl的转化率最佳。最后,通过密度泛函理论计算分析了反应路径,确定了反应机理。SiHCl3、(CH32SiHCl氯化反应的能垒差在于Cl2与SiCl3·、(CH32SiCl·反应的能垒,且Cl2与SiCl3·反应的能垒比与(CH32SiCl·反应的能垒高60.4 kJ/mol。

关键词: 二甲基一氯硅烷, 热氯化, 三氯氢硅, 氯气, 密度泛函理论

Abstract:

Removal of carbon impurities from trichlorosilane(SiHCl3) can improve the purity of polysilicon.However,the points of chlorodimethylsilane[(CH32SiHCl] and SiHCl3 are very close,and azeotrope is easily formed in the distillation process.Therefore,(CH32SiHCl in SiHCl3 is difficult to remove.It was proposed to use Cl2 as the chlorine source to convert(CH32SiHCl into high boiling methyl chlorosilane through thermal chlorination reaction to increase the relative volatility and facilitate the distillation.However,SiHCl3 and(CH32SiHCl were chlorinated at same time.Therefore,the change of the conversion of the two with temperature was investigated.The results showed that the conversions of(CH32SiHCl and SiHCl3 were 53.1% and 14.3% at 60 ℃ and 120 min,and the selectivity of(CH32SiHCl was the best.Finally,the reaction path was calculated and analyzed by density functional theory,and the reaction mechanism was determined.The difference between the reactions of SiHCl3 and(CH32SiHCl resulted from the different energy barriers for the reactions of the SiCl3· and(CH32SiCl· radicals with Cl2.The energy barrier of the reaction of SiCl3· with Cl2 was 60.4 kJ/mol higher than that of the reaction of(CH32SiCl·.

Key words: chlorodimethylsilane, thermal chlorination, trichlorosilane, chlorine gas, density functional theory

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