纳米MgO对六氟丙烷热分解性能影响及机理研究  

Effect and mechanism of nanocrystalline MgO on thermal decomposition characteristics of hexafluoropropane

作　　者：谈玲华[1,2] 李勤华[3] 杭祖圣[3,2] 高飞[3] 姜炜[1] 潘仁明[3] 李凤生[1] 

机构地区：[1]南京理工大学国家特种超细粉体工程技术研究中心,江苏南京210094 [2]南京工程学院材料工程学院,江苏南京211167 [3]南京理工大学化工学院,江苏南京210094

出　　处：《功能材料》2011年第7期1320-1323,共4页Journal of Functional Materials

基　　金：国家"十一五"科技支撑计划资助项目(2008BAK40B02);江苏省2009年度普通高校研究生科研创新计划资助项目(CX09B-095Z);南京理工大学自主科研专项计划资助项目(2010ZYTS015)

摘　　要：研究了纳米MgO在管式反应器中对六氟丙烷热分解性能的影响,用在线气相色谱(GC)、气相色谱-质谱(GC-MS)、离子色谱仪(IC)对热分解气体进行分析,采用X射线衍射仪(XRD)及X射线光电子能谱仪(XPS)对作用前后的纳米MgO晶型和组成进行表征。研究表明,六氟丙烷高温热分解时主要发生脱氟化氢(HF)的反应。在空管中随着反应温度的增加,六氟丙烷的分解率提高,而加入纳米MgO后六氟丙烷分解率均增大,在700℃时,六氟丙烷的分解率由空管时的23.9%增加到100.0%,同时热分解气体中HF的含量比空管时降低了42.4%。XRD及XPS结果表明,作用后的纳米MgO是MgO和MgF2的混合物。分析作用机理认为是部分纳米MgO与六氟丙烷热分解产生的HF进行反应生成MgF2,MgF2催化六氟丙烷发生脱HF反应。The thermal decomposition characteristics of hexafluoropropane were studied in tubular reactor.The contents of decomposed gas were studied by gas chromatography online（GC）,gas chromatography-mass spectrometry（GC-MS） and ion chromatography（IC）,while nanocrystalline MgO was characterized by X-ray diffraction（XRD） and X-ray photoelectron spectroscopy（XPS）.The results show that dehydrofluorinationg of hexafluoropropane is the main reaction and pentafluoropropylene is the primary product.It also indicates that the higher reaction temperature can promote hexafluoropropane decomposition in the empty tubular reactor.When nanocrystalline MgO is filled in the reactor,hexafluoropropane decomposition rate increases.As the reaction temperature increases,hexafluoropropane decomposition rate enhances.After nanocrystalline MgO added under 700℃,hexafluoropropane decomposition rate raises from 23.9% in empty tubular reactor to 100% and HF content in thermal gas product decreases by 42.4%.The XRD and XPS patterns reveal a composition system of MgF2/MgO is formed.The mechanism of MgO on the thermal decomposition of hexafluoropropane was preliminarily studied.That partial MgO reacted with HF and was transferred to MgF2 during the reaction.The resulting MgF2 are very active catalysts for HF elimination from hexafluoropropane.

关 键 词：六氟丙烷 气体灭火剂 纳米MgO 热分解 作用机理 

分 类 号：X932[环境科学与工程—安全科学]